How to remove the keyboard hinge cover?

Trying to open the DOPO 10.1 tablet monitor (tablet) from the keyboard the hinge is so 'sticky' it cracked the screen and the back popped open and magnets and insert tabs fell out. I replaced all but how do I remove the 'cover' over the keyboard hinge (the part with the monitor contacts) to lubricate it? Two hands are needed to swivel, open or close, the hinge. It's that tight. There are 5 screws to remove which I did but I still cannot remove that cover. Please advise. Thank you. Doc