Replacing weather seals on L lenses

[JohnLo]

Is it possible to purchase the rear rubber weather seal for an L lenses from Canon and replace it myself? How hard is it to unscrew the rear metal mount and put it back without screwing up any alignment? I'm looking at a used EF 24-105mm F/4L IS VI but I assume the technique would be the same for others.

Thanks

[ebiggs1]

"Only those who have done it before or have already made mistake doing it can do it."

Even the most experienced person had a first time.