You don't have to remove it, it just needs to be flattened out so it doesn't bear against the magazine enough to keep it from dropping free. You do want to have it in so that magazines cannot hang up in the frame when inserted.
CZ actually makes a flat part that goes in place of the mag brake, but it is cheaper to just bend the existing one flat.
This link should show you how to get at the mag brake and also how to improve the trigger should you find yours has excessive creep.