somehting like this...
edit: MAKE a BACKUP first

stop the services, and move all files to the new location (as root)
Code:
stop xxamp
mkdir /home/abc/opt
mv /opt/* /home/abc/opt
try to find references to 'opt' in your web-root...
Code:
# find any references to /opt (change files that have references!)
cd /home/abc/opt
grep -lir '/opt/' *
try to find references to 'opt' in your config-files...
Code:
# find any config files with references to /opt (change files that have references!)
cd /etc/apache2
grep -lir '/opt/' *