I just fixed mine a few weeks ago. It was easy. There are plenty of threads about this at Rangefinderforum.com.
1. Remove lens assembly
2. Soak in lighter fluid overnight.
3. Heat with hairdryer (on high) for about 5 minutes
4. Unscrew stuck threads. I was able to use my fingers. If still stuck, use more heat.
5. Clean old green gunge lubricant from threads using lighter fluid and qtips
6. Re-lubricate with synthetic grease |