It's just a special screwdriver bit or use the extractor (NOT THE DRILL) part of an easy-out kit
I think this set includes triangle bits:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=97517&xcamp=google&utm_source=googlebase&utm_medium=cpc&zmam=33951326&zmas=12&zmac=112&zmap=97517
extractor:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=40349
T-handle to hold extractor:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=38560
P, February 2010