I just replaced the 2 rear struts on a 2000 Monte. It was really pretty simple to do. I was able to get the entire strut assemblies for the rear left and rear right from Autozone for about $360.00 bucks and the entire job took less than 2 hours in the driveway.

For me personally I found it simpler just to purchase the entire strut assembly and completely replace the whole thing.

A couple things that made it easier for me was to use a 1/2 dr rachet with an 11mm(I think it was an 11mm it may be a different size) socket to undue the top strut nuts from inside the trunk. In my vehicle the studs are fairly long and not much room to get a 3/8 deepwell socket in to unscrew the nuts that are forward. The standard 1/2 socket had just enough clearance to get on the nut where a standard 3/8 was to short

Also the nuts that hold the lower strut to the lower arm are splined.

After you replace the struts you should get an alignment which I had a shop do for $60.00 bucks.