1999 Chevy Monte Carlo MAP Sensor

Hello,
1999 Monte Carlo Z34, 3800 MAP Sensor. I cannot get the 2 "funky" screws out that hold it on. They look like "STARS" but when I try to use a "star", it will not fit because there is something in the CENTER of the star. In the middle if you will, that prevents the bit from seating into the head of the bolt. Is this some special bit I will need to buy, or am I missing something? Thanks