'twould be nice if you had a link to some pix in your post - that's not a particularly common case though it is basically a stretch-Centurion done in Al.
. Like most cases, it is assembled with pop rivets. You can drill them out with an 1/8th inch drill bit, but be careful to get just the rivet as if you gouge out the holes in the case you'll need to use backing plates to keep the new rivets from pulling thru. You should try to get a grip on the back side of the rivet with a pair of pliers so the rivet doesn't spin when drilling Pop rivet tools and a supply of aluminum rivets won't cost too much or you could reassemble with some 6-32 screws and nuts of aluminum or stainless - you'll want phillips head or torx screws to keep the driver from slipping. You can get such at mcmaster.com, etc. or a well-stocked hardware store.
.b.h.