How would a person make a patch to upgrade their software in VB6?
The best way to do this, with the least amount of work, is to use a tool like Wise Solutions' SmartPatch utility, which comes with all versions of their installation toolsets. It takes care of creating the file to apply to modify your executable. Doing this manually would involve checking each byte manually against the new bytes in the new executable. It's not worth it unless you're really, REALLY bored.