How to redirect the Post New Thread button?

[Enthusify]

After a lot of hunting and trial and error, one of our team members just wrote a nice blog post with instructions on how to redirect the "Post New Thread" button in vBulletin 3 and vBulletin 4.

What was the reason we wanted to do this? We wanted members to use a new form in a new plugin that populates the subforum. Thus, we wanted the Post New Thread button within the subforum to redirect users out to the new plugin.