Not sure if you have to or not but I did when I changed my donuts and found one of my flex pipes broken. It wasn't that bad....getting the front bolt holding the exhaust hanger was way harder. Locating a heat shield was harder too...
I just put some penetrating oil on, let it sit and then loosened them off...came right away with no issues (although some of them are a little tight; especially the left most one).
I ended up doing copper exhaust donuts, new clamps, heat shield, one new flex pipe and flex pipe gasket.
I will make removal/installation of the front exhaust hanger screw/bolt and exhaust donut check a part of my annual maintenance from now on.