You'll need a spring compressor. Raise front of car. Put it on stands, have a method of jacking the front suspension after the car is up. Remove wheel, partially compress front suspension. Compress the spring, remove retainer nut and shroud from the top of the piston (under the hood). Unbolt the bottom of the strut from the wheel hub carrier. Remove the strut, pretty much reverse of removal to reinstall.
1987 BMW 325