So I'm finally getting around to replacing the bad idler on my z18. It looks to me like the bearing has actually partially disintegrated, and I think most of what is left is on the post marked in red. The teal is metal shavings I collected with a magnet on an inside out bag. Blue are circular rings, possibly washers, and purple look like rings but with little arches cut into their sides.

I'm assuming that I need to remove what is left on the post before I can put it in right? It seems fairly obvious but I dont want to take any chance of breaking the post as I dont have a way to replace that off the top of my head (although I'm sure I could find a way, even if I have to make a new one).

Also I am going to clean everything to remove any metal fragments I didn't get with the magnet, but I'm not sure if I need to lubricate inside the new idler or not. Any ideas?

I can post some different pictures if anybody wants to see some wrecked bearing/idler porn, or just wants a better look at some part of it.