So for us guys further north (~ 48ºN) we can just wait for summer and do the hot water soak!Lens off/on wouldn't have made a difference on my 414s - but soaking the gasket in warm water made it 1000% easier to get in the slot. .... but for my case (70F ambient), warming the gasket made a huge difference - it seated more or less as expected by reading the rest of the instructions.
I must be one of 'em! I've done four of our eight.I have talked to the factory and all they can say is use a plastic hammer and it's a bear even with their jigs, only a few workers do it.