1998 Explorer 4X4 found this in transmission pan how do I remove & replace it?

Transmission in 1998 Explorer 4X4 went out. I bought another from salvage yard. When I dropped the pan I found this:

Transmission shop looked at it & said it was a bearing. I still have the original transmission. How do I remove the part from it and put it into new transmission?

I would take it back to the junkyard have them get you another one. Thing is have no idea which thrust bearing is would be. You have to take it apart in tell found which thrust bearing is bad. But theres going to be more hard parts thats going to be bad too. To spit out a bearing I don't think you want to see what else is bad.
The only way you going to fix it will be using both trans to make one good trans hopefully. Take the trans back and save you a headache

Welcome to this forum! I agree that it's not worth rebuilding one that you just bought. You could rebuild your existing one, and forget about getting another one from the junk yard. A junk yard transmission is a gamble since you don't know why it was there in the first place.

"Junkyard trannies are often exactly where they belong"

It was actually out of an Explorer that someone had pawned to them but didn't come get (the salvage yard owner also owns a pawn shop) so I didn't think it would have anything wrong with it. BOY WAS I WRONG!! But the salvage yard won't take it back. I only had a 5 day guarantee, but couldn't start working on it until the weekend...which was the 6th day. So the only thing we figured we could do was take the 2 & make 1. But we can't afford to pay a shop $1500 (that's the cheapest we've found around here!) We'll just have to do it ourselves. Do you know where I might find ANY info to help? I've been looking for instructions, specs, component location details, and diagrams. I would GREATLY appreciate any help and/or suggestions.