I'm wondering if anyone can enlighten me how to remove the stock donut gasket that goes from the o2 housing to the downpipe?

This is my first work on an exhaust system and the gasket seems baked on there; my flathead screwdriver-prying method isn't working.

Thanks,
Chris

 

More flathead and hammer time

Mine took about 10 mins of beating on it, and some pliers to wiggle it off.. A little bit of PB blaster helped too

 

Great, thank you for the help; it took a lot more effort than I thought, but I got it off with your advice.