We just took ours out of our 2004 Itasca Sunova so might be similar. Couple of the screws were stripped but we kept working them until they came out. The cover came out pretty easy so no idea why yours is being a problem.
The TV was another thing. The bolts are on both sides and loosening them is a problem. I am sure they now have a tool for it but we just used what we had. DH and I just kept working until we got the cover off, the TV out, (it is very heavy) and now going to have one installed.
Looking for a mounting bracket that will drop the TV down for viewing. Think I found it today.
Love the sunshine and warmer weather!
Lynne and Jerry RVM 105
2004 Winnebago Itasca Sunova / 2012 Toyota Prius / 2016 ACME EZE-Tow Dolly