[ QUOTE ]
Spacemarine said:
Is there any special trick I don't know of?
[/ QUOTE ]
Yes. Heat is your friend.
Arc uses loctite (or something) to keep the retainer from backing out when you unscrew the battery tube. I guess when twisties were the rage, a turning battery could snag on the retainer and un-screw it.
Other threads have suggested using hair driers, heat guns or boiling water to soften the locktite first. You have to be VERY careful with heat guns beacuse they can be hot enough to melt solder. I've done that.
The boiling water method is to put the head in a ziplock bag that's rated for grester than 250 degrees. Get as much air out of the bag as possible before dropping it in a pan of hot water. Let it heat for 5 minutes or so, then try again. You don't want to melt the optics.
They make rubber jar lid grippers that may help you hold the head.
Good luck.
This message will self distruct in 10 seconds..... /ubbthreads/images/graemlins/wink2.gif