crwdns2893792:0crwdne2893792:0 Dan ,
Depending on the brand you may find sending them back to be resoled the better solution. LL Bean and others offer this. While one can take the old sole off with a knife, you need a heave duty sewing machine designed for shoes to sew the sole back on. You might find a local shoe repair store with the correct equipment. The hardest part is making the new sole water tight again.