The upper portion of the original Lotus Europa brake master cylinder is no longer available, so a substitution is usually used. I, on the other hand, from years of pauper existence, have the need to hack what's broken, usually to positive results.
This is no different.
Unscrew the billet aluminum from your brake fluid tank and let's get started.
Step 1: What You'll Need
The first thing you'll need to find is a cover that fit's the original billet aluminum housing. My wife generously donated a jar of Lemmon Pepper for the task. Unfortunately, she didn't realize she had donated it until the job was finished, so mind what you volunteer things from. Plastic is a much better choice than aluminum, which is what the original part was made from. As you can see, the cover lost the electrolysis battle, so a plastic replacement will be less bothersome for future owners of your car.
You'll also need four #6x 3/8" sheet metal screws.
If your car is stock, and you want to keep it that way, you'll have to find an aluminum screw-on cap. If you enter it in shows, you can eliminate the screws, but you'll have to clean up the original hardware.
A screw driver, sharp knife and/or Dremel tool, various cleaning materials and we're off to the races.
Step 2: Pry the Part Apart
The original plastic parts of the switch were held together with threaded rivets. These are easy to remove by prying the upper and lower plastic part apart. This switch has virtually no delicate parts or springs that will fly off if you do this. The rivets will simply back out of the lower plastic portion and the parts will separate. On mine, the float stabilization rod had rusted to the plastic cover, so I had to twist it with a pair of pliers until it broke free.
If your'e trying to keep everything original, put the rivets aside. If you're OK with new parts, you can toss the rivets.
You can also remove the contacts.