You can find good brake caliper wind back tool kit sets online at professional spare part stores. You can check with the following websites to find the right kits. Amazon has a great Brake Caliper Wind Back Tool Kit that is priced at $40 with free shipping. Alibaba is a professional trade website where you can get in touch with dealers who will send you estimates and quotes for buying the Brake Caliper Wind Back Tool Kit. You can also get in touch with local stores near your home by using Yellow Pages to find spare part stores. Automotive stores will always have the right kits that you can choose from.
For more info, see How to Retract Piston in Rear Disc Brake