Novice needs help

Looks like I may have located a 8.25" sure-grip rear end that I can pull a donor center section from. The guy selling says it's an 8.25" w/ 3:23 (assuming 3:21) from a '71-72 B-Body. My question is; is the center section a straight up swap into my '73 Swinger 8.25". If so, here's the real novice question... Do I just slide the axles out a little & unbolt the center section & it should just drop out? I've never been inside one of these but I'm assuming I can make the swap myself. Any help or guidance would be much appreciated. If I'm way off on the whole deal, please straighten me out. Thx.

~Jeff