I am using RapidSVN and did some commits including the creation of folders using a user account which I have since deleted, how can I change these so they are assigned to my new user account?
Not sure if RapidSVN can handle this, but on the command line you'd use svn propedit
svn propedit svn:author --revprop -r REVISION_NUMBER URL_TO_REPOSITORY
But you'll also need a pre-revprop-change
hook script which returns a zero exit code to enable it. Your repository admin will need to set that up.