Have you tried a 1/4" micro driver? I have found this kit useful in tight situations, if the torx bit can fit between the TPS and the cylinder head, this will usually work. You should check the TPS before installing to make sure it needs replacing. What gives you reason to think the TPS is malfunctioning?
This is what I used just a few weeks ago. My kit is made by Sunnex. No problem and whole swap out took maybe 20 minutes.