You can re glue using any 2 part metal bonding adhesive then use a self tapping stainless Hex-head screw through the injection hole....do not over tighten the screw.
This worked just fine for me for a season (17-20 rides).
Call Timbersled, tell them you are a Snowest member & they will hook you up with some nice lower A-arms. No need to change the stock uppers, they're a great A-arm.