|Is the catch on the top right corner/side of the printer main body; and you depress the (blue in the screen shots I viewed) "button" to release and open the cover?|
My feeling is that superglue won't work on that plastic... but possible you "may" be able to hold the two parts together with a small screw (pre drill a tapping hole for the screw first); then is the screw will hold the parts together - include superglue or similar?
As regards removing the cover itself, the user manual doesn't show any useful info in that regard. Some of these covers are hinged with a spindle through the "hinge/edge"; others sometimes area snap in fit onto the "spindle...?
I suggest you have a chat with Dell directly and explain the situation as they may offer a solution; not the least how to remove the cover and replace it with a new one; and also advise how much that cover will cost...?
Failing any/all of the above.. you may have to simply resort to an external strap arrangement to keep cover in place? I have a velcro system in mind...
Side note: the printer seems to resemble an earlier hp laser printer (early 2000-2005 vintage...).