This is a video on how to replace the rear shocks on a BMW E36, specifically this car is a 95 318I. 
In order to do this job you preferably need at least one jack stand and a jack. You can do jack each side up on its own or you can put the whole rear of the car on jack stands. Please note that you absolutely should replace shocks as a pair.
Removing shocks are quite easy, two bolts at the top, and a large 18 mm at the bottom. Please take note that you need to place some support on your control arm knuckle so it doesn't fall over when you remove the shock.