5k CDTQ: No brakes!

[Bruno Walter <bwalter@sfu.ca>]

A couple of days ago I was pulling into a parking lot and when I went
for the brakes and the pedal sunk limply to the floor.  The car is an 86
5000 CD Turbo Quattro.  I couldn't find any sign of fluid leaks, and the
fluid level is OK.  I've got a replacement master cylinder, as I suspect
this is the problem.  I've checked the Bently manual, and it doesn't say
much (nothing actually) about replacing the master cylinder.  I was just
wondering about the correct procedure, and any tips.

Please CC me at bwalter@sfu.ca or reply directly, as I'm not currently
subscribed to the list.