Community site. script version update plus htaccess issues

transfer scripts mods, over to upgrade php script. my script authors have updated their community script.. the upgraded php script is simmiliar to my old one, but some coding is different , which has lead me unable to install my mods, also user tables. 1. i wish for my old user tables to be installed into my new database 2. i have 3 php file mods ([login to view URL], [login to view URL], and [login to view URL]) that are needed to be coded into the new script 3. i am having a problem with my htaccess file or syntax , i.e. gaining user profiles url (i.e. [login to view URL]) i receive a 404 not found error. pls bid if you have expereince. thanks