20V rear differential mount

[TWFAUST at aol.com]

I was recently followed home by a 1990  90 20V Quattro, severely in need of a 
rear differential mount. I am having trouble removing the 4 tri-square bolts 
that hold the mount to the differential. The only tri-square tools I have are 
hexagonal "studs" about 3" long with the tri-square "star" on the end. The 
ends of these accept a socket to turn them. I can't get at the bolts with these. 
Is this just a matter of the wrong tool? Does anyone make these with a socket 
head? I can't find them anywhere.

Tom Faust