I think I may have made a mistake recently and completed a trade for a brand new Osprey Atmos 65... Normally, I would be ecstatic, but I totally forgot to check the size of the frame (I assumed the person I traded with had a frame that fit him). As it turns out, the frame is a large, and I am most definitely a medium. Is there any way to make this frame work, or should I just try to sell it and purchase one in my size?

For those interested, I am 5'9 and about 180