I know following code will remove all package from specific repo.
yum remove $(yum list installed | grep rpmforge | awk '{ print $1 }')
And following code will remove a package without dependencies.
rpm -e --nodeps "php-sqlite2-5.1.6-200705230937"
But i don't know how to use together.
Try the following command:
rpm -e --nodeps `yum list installed | grep rpmforge | awk '{ print $1 }'`