Just got my corsa cat-back in today...

[lrae]

But i cant figure out the best way to take the stock exhaust off. My problem is that I dont have a grommet puller so i cant take the exhaust hangers off. Whats the easiest way of taking them off without using grommet pullers? I wanted to get this thing on tonight, but it doesnt look like its gonna happen.
Thanks!

[likewater]

If the stock exhaust is anything like a B6, you don't need a grommet puller to get the hangers off. Some WD-40 or the like and a little elbow grease and they should come right off. Make sure you loosen all of the bolted connections that are holding the system in place as well. That will help you wiggle the exhaust around while trying this.

[MOFSTEEL]

A little bit of muscle and those hangers should pop out of the grommets.
...or you can unbolt the the hanger and grommet all together.
That way you can pull it all apart with the exhaust off the car.
If you do this make sure to label what goes where and in what direction.