Here is my attempt at rewriting the start of Glar's letter in more informal language:
"Yo, your language suсks major balls but we easily cracked that beginner code book you sent down. We also got questions for you dudes. How y'all even alive in that deadly light? Legends tell of surface dwellers but we always thought that was made up till now. We'd still think y'all was trippin' if our machines didn't straight up prove that hole above us leads to that deadly light. The whack death ray y'all sent shows your science mad basic. It's worthless to us except as proof you aliens exist. We only paid you in gold to be polite. That bread food ain't cuttin' it for our digestion, but that meat is the bomb. We'll trade double gold for all the meat you can provide. Send more ASAP."