Doing the aircon delete on my car and I'm stuck! I've taken the alternator and compressor off and am just removing the alternator bracket. There are two funny star bolts holing the tensioner in place. The bottom one came out with a 10mm spanner but it's the top one that I need out. The same spanner is loose on this one and a hex socket fits nice but can't put a ratchet on it due to no room. What have other people used to get this bolt undone?