At Arygle Street (opposite Kowloon Hospital/Chest clinic), there's a small alley (at the bus stop) which leads to Dunbar Road.
An old gentleman has a stall on that alley and he's a very good at shoe repair. You can try try!
Yes, I have tried before, the old gentleman is very kind and the price is very fair. If the qualify is no difference, I prefer give business to small shop (due to 人情味)