In reply to jon:
I dismantled a pair of old shoes. Quite easily done with a paint stripping/hot air gun.
Just give the old shoes a good blast of heat on the area you want to strip and the rubber should start to unglue. Peel away, heating as required. Possibly you could use a hairdryer or even pop the shoes in the oven!
Once you have a good length of rand, sand off any leather and old glue and clean it before glueing. If you have a bench grinder with a sanding or carborundum wheel, that's ideal and you can also feather the edges of the patch.
The heat gun has worked on a few brands of shoes ,bar one pair of Boreals that just didn't want to give in.