how to remove donut gasket from exhaust

Lisle make a tool, but most exhaust hangers can be removed by using a long screw driver or channel lock pliers can used to remove the exhaust hangers, I like to spray some silicon spray on them to make installation easier when refitting them. When opening any exhaust bolts, they have been subjected to lots of heat and are frequently stubborn to remove, be patient, use a good quality penetrate on the hardware prior to removing the nuts and bolts and use properly fitting sockets and wrenches, (six sided sockets as opposed to 12 point sockets will give better results). Work the bolts back and forth if they are stubborn and reapply penetrate, what ever happens don't brake off the hardware as it will increase the cost to properly repair.Use "never sieze" on hardware on reassembly. Autozone have popular vehicle manuals on line for free once you register on their website.