BMW E36 headlight assembly removal is a pretty easy and quick job. Headlight assembly removal is necessary when the headlight has been damaged or you need to remove the nose panel trim underneath it.
First you need to remove the tail light. The tail light is held in by a clamp that you need to press with a flat head screwdriver. You can leave the tail light dangling by the wire connector or disconnect the tail light connector. 
There are three 8 mm screws in the front at the top of the headlight assembly. Sometimes the insert will spin with the screw so you may need to hold the insert in place with a pair of needle nose pliers.
There are two 8 mm bolts at either end of the headlight assembly. Use an extension to access the bolts. 
There are two headlight connectors that you disconnect and then the headlight assembly will be free!
That's it, total time for bmw e36 headlight assembly removal should be approximately 20 minutes.