If you intend to sew it up yourself and you’ve never done it before, you’ll need the right needles, thread, and probably an online tutorial. It’s not an intimidating project, but it requires time and patience so the wool doesn’t pucker at the repair site. You could take it to a tailor if the cost to repair it is reasonable and less than the price of a replacement. Another option is to contact the manufacturer and see if the garment is covered under any protection or satisfaction guarantee.