I'm replacing all four of my door handle gaskets. Removing door panels was pretty simple but I wouldn't even attempt it without the right tools. Got the gaskets off (crumbled to pieces in my hands) and found that to get the new ones in place on the back side of the handle requires removing the pin that the door handle pivots on. It looks like a mess of a job as the end of the pin is "mushroomed" and not easily removed.
It appears that the new gaskets are "scored" so if one wanted to, you could cut on the score line, thus not having to pull the pin. Anyone done this before? Thanks!

 

Yes I cut the gaskets to replace them after reaching the same conclusion as you. That was about 4 years ago and they've been fine.

The H shaped part of the gasket doesn't appear to have any useful purpose when the gasket is installed.

I suspect trying to dismantle the handle would end in tears.

 

For once, my (severely) limited powers of reasoning were right. Thank you.

 

Could I ask which were the right tools you used to do the job - I'm guessing some trim tools and O-ring tool at least, in addition to the regular screwdriver and spanner set?

I've got to tackle this job pretty soon, and would be great to get a heads-up to avoid breaking any 20 year old plastic pieces