4 1/2" angle grinder on tile thin set...

I'm remodeling the bathroom floor and replaced all the subfloor except a little 2' by 3' section where the toilet is. I really don't fill up to it to pull the toilet out so I removed all the tile around the toilet. Since the rest of the room has the floor replaced I'm left with this small area to remove the thin set so I can lay vinyl flooring. Can I use a regular or masonry grinding wheel to remove this little amount of thin set? I really don't wanna pay $50+ for the diamond wheel I'm going to use once and on such a small area. I though my little mouse sander might work but it just tore up the 80 grit. I'm very much a newbie.