Volvo Repair: Replacing ABS Control Unit 1996 850, volvo 850, abs light

Question
I took my 1996 volvo 850 turbo into the shop because the ABS light and the Tracs off light have been going on and off for a few days. The mechanic told me I need a new control unit and quoted me $500.

I looked online to see if I could get the part cheaper and I found a bunch of places that rebuild the CAB part of the unit for around $100. I also found a wholly rebuilt unit for $200.

How hard is it to replace an ABS control unit? Is a rebuilt control unit a good idea? The sites recommend using a Torx e5, but say that a six-sided socket wrench will also work. Is that true?

I have a little mechanical skill (I can read a Chilton guide and for the most part follow the instructions) and there are 123k miles on the car.

Answer
Hi Lorelei,
          I like the fact that you are a hands on person.
    I'm reluctant to support you in your desire to do this job...replacing brake parts on a complex braking system is a exact repair job...no room for error.
         I have little experience in doing this job.
          So,Lorelei I'm say good luck in solving your brake problems...You should buy part and let a fully competant repairperson do the job.
                 Bilbo