If you've got a large metal object covered in paint or another material and you need to strip it down to bare metal, one option is using a wire cup brush installed on an angle grinder. By pulling the trigger on the grinder, the wire cup brush turns at a high RPM, blasting away the paint on the surface quickly. Installing the wire cup brush takes under a minute, and then you'll be ready to strip some paint.
Unplug the angle grinder from the wall and place it upside down on a work surface so the trigger on the grinder is facing up.
Find the shaft lock, which is a button to the side of the angle grinder by the head. Push down the button and use the lock nut wrench included with the angle grinder to remove the bolt on the center of the grinder. Take off the nut, washer and any grinding discs present.
Hold down the shaft lock again with your hand. Thread the nut on the wire cup brush onto the threaded shaft of the angle grinder. Tighten down the wire cup brush onto the angle grinder using the wrench included with the angle grinder. Plug in the angle grinder and now the wire cup brush is ready for use.