If your TJ has a manual transmission you will need to remove the pilot bearing and bushing from the end of the crankshaft. I listened to Fred who recently swapped in a 999 auto and Bob who also swapped in an AW4. Both of them used a chisel to break it. I thought I'd try something different. I drilled 2 holes not quite as big as the bushing is wide into the bushing. Then I used a sharp chisel to break the bushing at the holes. It worked like a charm. Once the bushing and bearing are completely removed use a small file and some very light sandpaper to make the inside surfaces smooth again.
Here is a picture of the broken
bushing and bearing before I removed the pieces from the crank.
4x4 Off-Road Homestead Firearms RC Flying