Easiest way to patch your own hooks into the vBulletin codebase?

[vbSuperfan]

vBulletin tells me that it's completely impossible to modify the contents of posts displayed in the Mobile Suite mobile apps, either by hooks or class extension plugins for the vB5 back-end (which serves the contents to the mobile apps through the API requests that these apps make to it).

Based on this information, my only remaining alternative is to patch the vBulletin code myself, and the cleanest way I can think of is to insert my own hook point(s) into the vBulletin source code and then reference these from an extension/product, thus causing minimal patches of the vBulletin code itself, which can be repeated for future released versions of vBulletin as easily as possible.

My question is therefore:

What is the easiest way to patch your own hooks into the vBulletin codebase? Is there only some single line of code I can insert at the location in the code that I want to hook?

Is there perhaps even some examples available somewhere that I could take a look at in regards to this topic, that anyone knows of?