Q.rooting jade
Taking a portion of a Gollum jade plant to re-root. How do I separate and replant?

Re-rooting Jade plants is one of the easiest things to do, and the only thing that's different about a Gollum Jade is that it will be a bit more tedious to get as far down to the base of a cutting as you'll need to.
Consider taking this as an opportunity to repot your Gollum Jade. Most plants are easy to work with while they're out of the ground or the pot. If repotting isn't an option, start around the outside of the plant and prune inward, cutting as far down to the base as possible.
It will be challenging, but it can be done.
This article will give you some tips on rooting Jade cuttings:
https://www.gardeningknowhow.com/houseplants/jade-plant/propagating-jade-plants.htm