Im replacing the rear wheel speed (abs) sensor and i cant for the life of me figure out what kind of socket/bit you need to get the bolt out. It's almost like an inverted tork bit...
It is a special E8 External Torx bolt. I bought one just for this job.
However, you can use an 12 point socket (just don't ask me the size but its small). It will not fit perfectly but should work well enough. A 6 point socket will not work.
Note, there is red lock-tite on those bolts. The removal force will much greater than normal for such a small bolt. Enough that I was concerned about stripping the bolts.