very handy for backporting code fixes, these steps will allow you to switch with relative ease between multiple versions of WebGUI.

step 1 stop everything

wreservice.pl --stop all

step 2 get your new code

svn co https://svn.webgui.org/plainblack/branch/WebGUI_7.5 WebGUI_7.5

step 3 link to the new code

rm -f WebGUI ; ln -s WebGUI_7.5 WebGUI

step 4 add a new hostname

edit /etc/hosts add local7_5 to the line starting with 127.0.0.1

step 5 get a copy of config files

cp /data/WebGUI.beta/etc/*.conf /data/WebGUI/etc/

step 6 start mysql

wreservice.pl --start mysql

step 7 add a new site

addsite.pl --AdminPassword=123qwe --sitename=local7_5

step 8 start everything else

wreservice.pl --start modperl modproxy spectre

step 9 configure the new site

browse to http://localhost/ and follow the steps to configure the new site

switching sites

with this setup you can only run one site at a time because they all use the same network ports.  but switching is very easy using  switch_webgui.pl which is attached.  simply pass as an arguement the directory for the new WebGUI code you want to run and it switches everything and restarts everything.