First things first... there should be no need for a grinder here.
Now what don't you like: the front sight base or the front sight post?
If you don't like the front sight post, you can replace that with a thinner match post.
If you don't like the front sight base you can replace it with a low profile gas block, a picatinny base gas block or flip-up front-sight gas block.
The standard FSB is held in place by two taper pins which are driven out from left to right. Make sure that the barrel/FSB is SECURELY held in place before you start whacking away...those pins are probably going to be tight.