Okay, the lens is not replaceable, the whole Bezel has to be replaced.
I suggest that you call SureFire Customer Service to ask for the full part numbers so that you can order the parts you want through your dealer.
E2 Bezel Assembly base number = 13749
[You need to find out the dash number for the colour Bezel you want.]
The o-ring rings are 19-01-052 & 19-01-084.
I hope this helps.
Al