How to disassemble Mares X-Vision mask

Does anyone know how to do this? I have a replacement lens, and I can't figure out how to take the outer retaining part of the mask without breaking. Thanks for any help.

When you bought your optics, each lens should have come with a black plastic tool. Use the WIDE end of the tool to carefully pop the front plastic retaining ring off the front of the mask. Insert the tool between the ring and the frame and pop out the little tabs that hold the ring to the front of the mask. There are 4 tabs on each side of the mask. Then just push the old lenses out and replace with your optics. Replace the retaining ring and pop the tabs back in and you're done.

A fingernail will also work but hurts more.

Thanks for the tip!