8.8 swap questions

Hey guys/gals as most of you know I'm doing a 8.8 swap for my dart because I cant afford a 8.75 and I know my 7.25 ain't gonna hold up. So I picked up a 8.8 last summer out of a explorer for 100 bucks it's a 3.73 limited slip disk brake 31 spine rear. I was searching fb marketplace the other day looking for a right side axle for my altercation. And I found a entire complete rear end for a 100 bucks the same price as the axle is new. So I bought it today. I now two of them both are 3.73 gears and disk brakes out of an explorer. The new one is not a limited slip it's an open which isnt no big deal because all I want is the axle. Here is where it gets tricky and where my question is. The new one ( the open diff) Is in alot better condition on the outside the other one is covered in surface rust and has pieces of rust chipping off it. This one is clean. Looks like it will be an easier rear to clean prep cut and paint. How hard is it to swap the limited slip differential into this new housing? Is it something I can do at home with basic tools ? Does it require any machine work etc? I have never been inside a rear end so this is a new one for me. Thanks