A small fix using assembly language for PowerPC (OSX)

The task is to remove a time expiry lock on a demo version of a small program, but it is not as illegal as it sounds. The programmer/owner of the software is somehow out of business and unable to supply a normal version. I have managed to reach him on an old work-email but he could not supply, and now he is completely "gone of the radar". At the time when he sent me the demo version he was very happy that I wanted to use his software. Whenever he will be in a position to sell me the licence I will offcourse pay him. It is a CGI compiled for PowerPC (PPC - Mac OSX). The disassembly is full of C-like comments and other comments, so it is easy, even for me, to see where the expiry-lock is. I think it will be an easy task for somone who knows assembly language for PowerPC and has the right tools. I prefer that somone who really knows assembler for PowerPC bypasses the date-lock routine entirely, but I will settle for just changing the expiry date if that is all I can get. I do not want somone who only knows assembler for x86 to try to do anything more sophisticated than changing the expiry date. So, please specify what kind of job you can do; bypass or date-change.