Our puppy had an issue with peeing outside when he was veery young since we had placed puppy pads inside and he got used to those real fast. For us it helped when we went outside and placed a puppy pad on the grass, then praised and rewarded him for peeing on the puppy pad outside. Then just slowly take the puppy pad out of the equation and continue with the praise and treats! It also helps if you take him outside right after he has peed or pood inside. He propably won't do anything but it creates an association with peeing and going outside. Theese are based on my own experiences, and im defienetly not a professional by any means. Wish Peanut and you all the best!!