I clamped a piece of wood in place and using that as a guide for the disc cover on the grinder I got better results than I was hoping for.
All with a cheapo Lidl 4 1/2 inch grinder, and one of a 4 pack of discs they were selling for not a lot of money.
It's often the jobs you dread and obsess about turn into the easy ones whereas the "10 minute jobs".....