Impact driver with torx socket.
Sears.com
these things are great and the very best way to deal with torx bolts. You just hit it with a hammer. It turns while keeping the bit in the hole at the same time. greatly reduce the chance of stripping the head out. will sometimes even work on stripped heads if there is anything left at all. like the ones some moron tried to remove with an Allan wrench.
always buy the best torx sockets you can find, cheap ones will twist right off or snap. I have a set of Kobalt I have found work well, would go with Craftsman or Snap on (for the independently wealthy).
for torx heads this works way better than an impact wrench.
best penetrating oil ever 50% acetone 50% ATF. Have to keep it shook up and sealed or the acetone goes away pretty quick.