Update Zabbix with a script

I need to make a script that will update Zabbix on Ubuntu. It needs to update everything like the log files and so on. But I don't know how to make a script that will execute this. I've been trying to look up information on this subject but can't find anything.
Solution
Following is an old script that is used to install Zabbix-server automatically, but only for the first time, I think you must only edit thing which is required in the application
#!/bin/sh
#
# zabbix 2.0.2 install with postgresql and jabber support
#
# 
# software distributed under the License is distributed on an "AS IS" BASIS,  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND
#
# written by:
# Stefan Krueger 
# tested on Debian Squeeze/Wheezy & Ubuntu 10.04 LTS/12.04 LTS (use sudo su -)
#
(
dbpw=$(dd if=/dev/urandom bs=1 count=6 2>/dev/null | openssl base64)
zbxver=zabbix-2.0.2
ipadd=$(env LC_ALL=C /sbin/ifconfig eth0 | sed -n '/addr:/s/ [^r]*..//gp')

date

# update system
echo '###############'
echo 'update system'
echo '###############'
apt-get update 

# install requirements
echo '###############'
echo 'install requirements'
echo '###############'
sleep 1

apt-get install -y postgresql build-essential fping apache2 php5 php5-pgsql php5-gd libsnmp-dev libcurl4-openssl-dev libapache2-mod-php5 libiksemel-dev libpq-dev libssh2-1-dev libopenipmi-dev

#DB setup
echo '###############'
echo 'database setup '
echo '###############' 
sleep 1    

adduser zabbix --no-create-home --system --group --disabled-password --shell /bin/false --quiet && echo 'User zabbix created' || echo 'User zabbix could not be created'

su postgres -c "echo \"create user zabbix with password '${dbpw}' createdb;\" | psql" && echo "database user zabbix created" || echo "database user zabbix could not be created"
su postgres -c "echo \"create database zabbix with owner=zabbix;\" | psql" && echo "database zabbix created" || echo "database zabbix could not be created"
sleep 2
#  zabbix installation

echo '############################################################################'
echo ''
echo $zbxver installation
echo ''
echo '############################################################################'
cd /tmp/
mkdir -p /tmp/install
cd /tmp/install
wget http://prdownloads.sourceforge.net/zabbix/${zbxver}.tar.gz
tar -zxvf ${zbxver}.tar.gz

chmod -R 777 /tmp/install/* 
su zabbix -s /bin/bash -c "psql -d zabbix -f /tmp/install/${zbxver}/postgresql/schema.sql" && echo "create schema success" || echo "create schema failed" 
su zabbix -s /bin/bash -c "psql -d zabbix -f /tmp/install/${zbxver}/postgresql/images.sql" && echo "create schema success" || echo "create schema failed" 
su zabbix -s /bin/bash -c "psql -d zabbix -f /tmp/install/${zbxver}/postgresql/data.sql" && echo "create schema success" || echo "create schema failed" 
cd /tmp/install/${zbxver}
chmod +x /tmp/install/${zbxver}/configure
chmod +x ./configure
/tmp/install/${zbxver}/configure  --enable-server --with-postgresql --with-net-snmp --with-libcurl --with-openipmi --with-jabber --with-ssh2 --enable-agent --prefix=/usr --mandir=\${prefix}/share/man --infodir=\${prefix}/share/info --sysconfdir=/etc/zabbix || exit
make install
#install frontend

echo '############################################################################'
echo ''
echo '$zbxver installation'
echo ' FRONTEND installation'
echo ''
echo '############################################################################'
sleep 1

sed -i.backup -e "s/post_max_size = 8M/post_max_size = 32M/g" -e "s/max_execution_time = 30/max_execution_time = 600/g" -e "s/max_input_time = 60/max_input_time = 600/g" -e '/date.timezon/a\date.timezone = "Europe/Berlin"' /etc/php5/apache2/php.ini

cd /tmp/install/${zbxver}/frontends/php

mkdir -p /var/www/zabbix
cp -a . /var/www/zabbix
chown www-data:www-data -R /var/www/zabbix
cat <<EOF > /etc/apache2/sites-available/zabbix
<VirtualHost /zabbix>
        ServerAdmin webmaster@localhost

        DocumentRoot /var/www/zabbix
        <Directory />
                Options FollowSymLinks Indexes MultiViews
                AllowOverride None
        </Directory>
</VirtualHost>
EOF

echo '############################################################################'
echo ''
echo '$zbxver installation'
echo ' services  installation agent & server'
echo ''
echo '############################################################################'
sleep 1
mkdir -p /var/log/zabbix && chown zabbix /var/log/zabbix && chmod 760 /var/log/zabbix
mkdir -p /var/run/zabbix && chown zabbix /var/run/zabbix && chmod 760 /var/run/zabbix

#cp /tmp/install/${zbxver}/misc/conf/zabbix_server.conf /etc/zabbix
#cp /tmp/install/${zbxver}/misc/conf/zabbix_agentd.conf /etc/zabbix

sed -i.backup -e "s|DBUser=root|DBUser=zabbix|g" -e "s|# DBPassword=|DBPassword=${dbpw}|g" -e "s|/tmp/zabbix_server.log|/var/log/zabbix/zabbix_server.log|g" -e "s|# PidFile=/tmp/zabbix_server.pid|PidFile=/var/run/zabbix/zabbix_server.pid|g" -e "s|# HousekeepingFrequency=1|HousekeepingFrequency=24|" /etc/zabbix/zabbix_server.conf

sed -i.backup -e "s|/tmp/zabbix_agentd.log|/var/log/zabbix/zabbix_agentd.log|g" -e "s|# PidFile=/tmp/zabbix_agentd.pid|PidFile=/var/run/zabbix/zabbix_agentd.pid|g" /etc/zabbix/zabbix_agentd.conf

chown -R zabbix:zabbix /etc/zabbix
cp /tmp/install/${zbxver}/misc/init.d/debian/zabbix* /etc/init.d/
sed -i.backup -e "s|/usr/local/sbin/|/usr/sbin/|" -e "s|PID=/tmp/|PID=/var/run/zabbix/|" /etc/init.d/zabbix-server
sed -i.backup -e "s|/usr/local/sbin/|/usr/sbin/|" -e "s|PID=/tmp/|PID=/var/run/zabbix/|" /etc/init.d/zabbix-agent

chmod 775 /etc/init.d/zabbix-server
chmod 775 /etc/init.d/zabbix-agent
update-rc.d zabbix-server defaults 90
update-rc.d zabbix-agent defaults  99
/etc/init.d/zabbix-agent start
/etc/init.d/zabbix-server start

/etc/init.d/apache2 restart

echo ""
echo ""
echo ""
if [ -e /var/run/zabbix/zabbix_server.pid ]; then echo "  zabbix-server started succesfully"
else echo " !!  zabbix-server dont start"
fi

if [ -e /var/run/zabbix/zabbix_agentd.pid ]; then echo "  zabbix-agentd started succsfully"
  else echo " !!  zabbix-agentd dont start"
fi

echo " look at the zabbix_install.log"
echo ""
echo "  please configure you postgresql.conf"
echo "  the database password for zabbix is: ${dbpw}"
echo ""
echo "    now you can configure the zabbix-frontend http://${ipadd}/zabbix"
) | tee zabbix_install.log