Hi, looking for some advice regarding brake callipers.

I asked my garage to do a brake fluid change, but they didn't want to tackle it as the bleed nipples were severely rusted, and the fear was that they would shear off. Was advised that should this happen, I could need 4 new callipers, at around £100 each.

Does anyone have any advice on how to remove the nipples when they are in a poor state? I've thought about WD40, and applying heat, but understand that this can make the brake fluid boil.

My other thought was to try to obtain a full set of used callipers from ebay, and refurbish them myself in preparation for swapping over towards the end of the year, but there seems to be a few different types, and a year change which I believe occurred in '95 (please correct me if i'm wrong). The car in question is a 1996 Mk3 Golf Gti 8v with the AGG engine.

Any advice on which type I need, and any other relative advice, would be much appreciated.

Regards,
Scoobysnax