I took this picture kinda at an angle so you all could see parts of it. If you look inside this collar, you can see it is threaded and there is an internal threaded sleeve with a cut on both sides. The driver bit is this picture fits is perfectly. Th OD of this collar is 3/4 inch. I do not want to mar any of it up. I need to hold this so I can unscrew the sleeve - I have a strap wrench but it just don't go that small. Ideas?