i bought a powercab plus 112 recently and i need to open it, something has come loose in transit,  how do you open one of these, on the out side other than the ones on the handle, there are about 6 screws,   3 on the back,   3 on top.   there was someone who asked the same question on this forum and the answer was use a butter knife to wedge it open.   where do you start from is this thing glued all the way round. does the grill come off     has