I do this the old fashioned way because I lack money for fancy food processors and I like the physcial act of grating the cheese. It smells amazing!
Unwrap your cheese and cut the rind off. Put the rind in a plastic bag. You can keep this in the freezer and use it in soups! I recommend putting it into a herby bean soup - those are the best!
Then, cut your cheese into two smaller pieces if it's especially large.
At this point, either tear off a sheet of parchment paper or use a large plate to set the grater on. That way, you'll be grating onto a surface that will allow you to dump the cheese right into the pot.
So grate away! Eyeball the amount. Use less or more according to your level of cheese desire.