I think he may mean the module, not lens.
If that's the case, the heatsink has a set screw in it. Tighten that on to the module and it will stay secure.
*Edit* I saw earlier posts suggesting this may not be the problem. If your heatsink is like mine, Mr. Juice, I might know what you're talking about. I remember when I got my heatsink for a C6 from Moh that it was a little too short in the front so it would spin. What you could do is take an O-ring that fits around the back part of the heatsink and bring it up to the backside of the heatsink's lip and that should hold it securely in place whilst in the host.
As for determining wire's polarity, ask Moh. He made the kit and probably knows. Or take the driver out of the pill and check.