I hope since it is a 1987 that these have been done a few times before since they are notorious for wasting ball joints and idler arms.
If the uppers are original they are riveted onto the upper control arm. The fastest way to remove the rivets is a torch to heat up the rivet and an air hammer and a chisel bit to shear off the end of the rivet. A drift punch will then drive the rivet out.
The new ball joints will come with bolts to install.

Lowers are pretty straight forward.

Because the ball joints are usually replaced every 30k or so on the S-10/15 series there is also a chance you might need the oversized lower ball joints if the lower control arm is loose where the joint installs.

Book time if I recall on the 4x4 was close to 2 hrs per side for ball joints. After the 1st 100 trucks they can be done in about 20 min/side. Don't forget to check your idler arm as well, its probably toast.