To us as bass players, we know that pulling the control cavity cover off is no big deal. The problem you could run into is that the seller can now tell an arbitrator that you "ripped it apart" and if the arbitrator has no idea about guitars / basses, you can appear to be at fault. In general, it's best to stop as soon as you find an issue and contact the seller. see where they want to go from there. If you can show that you signed for it at 3:18 and at 4:30 you're emailing the seller with an issue, there is not a lot of chance that you broke it. PayPal / eBay would easily side with you. They'll most likely still side with you.