I wrote up some stuff for my website on my disk conversion. It’s not much, but it’s at
http://www.oldsub.com/Content/2002/11/brakes.html. I pull the transmission cover and us a funnel to fill the master cylinder. I have an extra battery cover, and have thought about modifying the floor and using that cover for the master.
Another approach is to cut another round hole and buy an additional round cover just like the stock one, but locate it to fill the new master.
Remote fill masters are another solution. You mount the reservoir somewhere easier to service, and then you don't need to get underneath.
If your brake lines are good and your calipers and cylinders don't leak, you don't need to deal with it very often...
