You could just cut out a small amount and but the rest together, or just wear some bracers over it to fix the bingo wing problem. They sell metal bracers really cheaply at mercenary's tailor but i'm not sure if they'd be period except maybe for the LATE 13th early 14th century. I plan to do the bracer fix myself till I get icefalcon rings and rivets to tailor my own maille.
Ulrich, if you're going to try to use bracers as a way of keeping your mail in check, might I suggest some ties - Sir Brian showed me a way to do so, which will bring the mail closer in to your arm and may help with the bracers. The bracers themselves look as if they
should do a good job of keeping the mail down but it doesn't, at least mine did not. In the course of the day, moving around, lifting your ale the mail just finds a way to slip out. Plus, with having to wear the bracer looser than normal the weight of it sits on the wrist rather than distributing over the arm that's covered which can get painful as time wears on.