I'm trying to replace my muffler hangers with my new stainless steel ones, and for the love of me, I CANNOT get the 2 bolts off, it seems theres a clip behind them that keeps them from screwing out?

Do I have to take off my cat-back to change these? Or should this be possible?

This is the part I'm trying to replace:




[IMG]local://upfiles/49968/1FE2229EFD654FCA9E36E71805B0FAAE.jpg[/IMG]

 

I can't tell anything by the picture but try using vise grips to hold the parts thet keeps turning.

 

I think I'm just using the wrong size socket. I'm using a 10mm, but its a star pattern, I think I need a hex.