<https://cinematography.com/index.php?/forums/topic/89650-lens-step-up-ring-stuck-with-little-leverage-room-to-remove-it/#comment-551401>
<http://schema.org/text>
"If rubber tools using friction won’t work, the simplest, non-damaging thing is to just drill two small holes in the flat surface on opposite sides and then use a lens spanner wrench, which you can buy on eBay for as little as $10. I’ve done this dozens of times to remove difficult lens lock rings and other things. It will undo the ring and leave the threads undamaged if you ever need to use it.\n \n"
<https://cinematography.com/index.php?/forums/topic/89650-lens-step-up-ring-stuck-with-little-leverage-room-to-remove-it/&tab=comments#comment-551289>