O-rings... having dealt with diving lights and cameras for a while, the best way to remove an oring
is to finger it off (NOT fingernail). If it will not come off with a nudge, then the next best thing is to
use the rounded end of a credit card to get it up and out of the channel it is in. The best lube for
an o-ring would be the stuff you buy at a dive shop. I am not sure what it is (environmental silicon?), but
you can get a tube for cheap at any dive shop.
