I have a very small circuit in my house. Probably 8 outlets 6 lights. The breaker for this circuit has a direct short somewhere. It didn't start this way. At first it would stay energized for a couple of minutes then trip. The more I reset it the shorter it would last. Now it trips immediately. I can sometimes see an arc when I reset it. I have replaced the breaker, I have removed three of the light fixtures and pulled out 6 of the outlets from the wall to inspect them. I removed one of the outlets. Besides removing all of the fixtures what is the best way to troubleshoot the problem. I should mention that most of the light fixtures have 2 or 3 way switches.

Seriously, an Electrician should be able to narrow it down pretty easily and safely.

It's not something that can be explained in a few words, and it's beyond the scope and purpose of this Forum.