If you look, the cap on top is just a stamped steel part & easily taken off. Just pry it back enough at the bottom where it's crimped & pull it off. You'll see the top of the tube has a flair that keeps it in place with the crimp when it's on.

Just make sure it's clear inside. Nothing in there. If it get clogged it'll build up pressure in the rear & force fluid out somewhere you don't want.

I always clean them if I'm there just to make sure, too easy.

Butch