Bilstein/H&R conversion: What parts to re-use?

[Ameer Antar]

I'm upgrading my 5kT front suspension Bilstein's and H&R springs, and I'd like to know what parts I need to reuse. I know the bump stop isn't needed, but how about the lower washer that goes above the bump stop? I know the upper washer is needed for the strut mount, but not sure about the lower one. Also is the round plastic cover (goes over the strut cap) needed for the boot? Anything else I should delete from the new setup? TIA.

-Ameer