Well, Mighty Gryph, I don't know if easy peasy is the right description.
What I did was squeezed the lens and bucket together whilst my son-in-law forced the clips over with his big meaty paws. But it did get done. Makes me wonder if I have too many seals? I have one round cross section one and one sort of square cross section. The round one looked like it had been super glued in at one point. It took fair bit of pressure to git 'er done.
But done it is.