How do I get the cover off of the paint roller?

The cover has plastic base that slipped onto the roller easily. But now that I'm done painting it won't come off. Also, can I clean up this roller and use it again or are they one use things?How do I get the cover off of the paint roller?
I use a piece of foil or plastic wrap, wrap it around the roller holding it over the trash can and pull it off...you really have to pull hard, especially if you've let the paint dry some. You can clean up the roller if you want, but they're pretty inexpensive and it's alot of trouble. I throw them away!How do I get the cover off of the paint roller?
If you want to reuse it,


take it out side and use the garden hose to rinse all paint out of it while it still on the roller.


If it has dried paint in it, toss it out.


To remove it you just ,puulllllll on it.


When I wasnt ready to deal with it I just stuck it in the water tank on the toilet . to keep it wet until i was ready to clean it.