Have you ever had a wool sweater that shrank? Well, I made a mistake and put my wool sweater in the regular wash, and as you can guess when it came out it had shrunk two or three sizes. I didn't think there was any hope and was going to give it away when I found the below solution. It worked really well and now my sweater is the correct size once again. :) I hope this is helpful!
Without rinsing the sweater, take it out of the soapy water and roll it in a towel to remove as much moisture as possible.
Lay the garment out on some towels in a cool place. Stretch the garment out to its original dimensions pulling it into the size and shape you want. Fasten the sweater to the towel using pins, being careful not to snag the sweater. (As shown) The absence of heat from the drying process allows the wool fibres to set in place without locking together and shrinking the garment again.
Return to the sweater every several hours, re-stretching and re-pinning it as necessary, until the sweater is dry.
You will have a good as brand new, fully functional sweater again! :)