cats

We've got one cat 6months and the other 3months old, currently both using the litterbox. However we're going to move to a new house soon, and eventually try to transition them to getting used to doing their business outdoors instead of the litterbox. Does anyone have any tips or best practices for this transition?

Edit: I dont live in the US, I live in Scandinavia - huge garden and away from traffic. The cats are fine being outside - most cats here are in fact outside. We have norwegian forest cats and they're meant to be both indoors and outdoors - even during winter!

https://en.m.wikipedia.org/wiki/Norwegian_Forest_cat