I bought a blue line SVT this summer (hooray!) that I haven't really been playing recently because the fan makes nearly as much noise as the amp. So I bought a replacement from Fliptops and started trying to install it myself. Here's the pathetic part - I can't even get the rear grill off. I took out the Phillips screws on the grill itself but it looks like the grill is also secured by the bottom black panel, which is possibly held on by these hex-type screws that I can't get to turn. They're old and basically have nothing to grab on to. Do I even have to remove these or is there something I am completely missing here? Picture is attached. Thanks for any help with my ignorance here.