playdeep,
According to this thread,
http://forum.ppcgeeks.com/showthread.php?t=4201, Colonel's 3.5 final did not include Arcsoft or anything else in the extended rom - you were to let these run automatically after the hard reset (i.e. Don't interrupt the customizations).
If it's been installed already, then you should see MMS in your Outlook account list (or in Outlook, go to folders and see "MMS" at the top.)
Unlike Sprint's, the Verizon ExtRom has very little garbage in it (spacewise, that is). As long as you continue to run Colonel's 3.5 with no built-in customization and you want MMS, you should leave your Extended Rom alone and let the customizations run after a hard reset. If you accidentally interrupted them, you can manually run the Arcsoft cab and other recommended cabs listed in the sticky. If you really want to start messing with the Extended Rom contents (i.e. "nuking"), imo you would be much better off just rebuilding the rom using helmi's 3.5 kitchen - virtually all of Colonel's stuff is in there. Then you could unlock and clear out the extended rom and use it for installing other programs or whatever.