We have a 2003 Born Free with the original Dometic manual awning. A few weeks ago the awning was damaged in an accident. The lower mounts were pulled out, completely detached from the fiberglass bod...
I think you might be able to get the arm back down by flipping the ratchet lever on the awning roller to the other position, if you haven't tried that already.
Taking the awning off is not really hard in a theoretical sense, though it surely would be a cumbersome process. Basically the structure gets unbolted and the fabric slides out of the groove in the mounting bracket on the motorhome. The usual fun of dealing with caulking, rusty fasteners, poor access to bolt heads, etc. may apply.