How to remove a dental crown by yourself? Have semi-permanent dental crown attached to my upper jaw and food keeps getting stuck

It's my advice to visit the dentist, do not try crown removal at home. It may result in breakage of the root. Also, discuss your concern with your dentist.

Hi:It’s best to go to a dentist to attempt removal of the semi permanently crown.  You might break the tooth if you attempt to remove it yourself.Best,Dr. Maddahi

It sounds like you have a bridge or fixed partial denture that has become loose. This is probably because one or more of the teeth under the bridge have a large cavity and no longer bonded to it.  These devices can routinely catch food debris if not properly cleaned regularly. I would not advise removing this by yourself. This could easily break off any remaining healthy teeth you still have it attached to and effect the future treatment options. A medicated mouth-rinse and diligent cleaning can help stabilize the problem until you are able to get into an office and have a dentist remove it for you.