Look up phimocure and order a set. About $40 delivered. Start stretching it out. Take it easy and don't be too ambitious, over-doing it will set you back. Use a good moisturiser with the rings, one that doesn't irritate the skin.
It took me about a year to go from almost closed to fully functional, with no need for extra stretching once done. Made big gains quickly then progress was slow but steady. Pleased I didn't listen to the urologist who said the chop was the only option.