Start by removing the front fascia ring of the lens using a rubber fraction tool.

If you do not have a tool like this, find a rigid object of about the right diameter. Sandwich a piece of silicone or rubber between that and the lens for a makeshift solution.

The fascia ring is made of plastic, and so can skip in the fine pitch threading if too much pressure is applied.

If this is an issue for you, unscrew the fascia ring as far as possible, then carefully place a pry tool in the gap, placing a piece of paper or similar over the lens element to protect it. Then you can pry on the ring to get it to bend slightly and come out of the threading.