Thanks, Andyxlh and Brendan, for the advice.
Have progressed a little bit further and should be ok for a little while on the upcoming steps.
However I note that there’s no wiring info with the Tonerider TRP1 Pickup upgrades and the wiring diagrams on the site don’t specifically reference the PB30, (very possibly because it’s a new item in the range). Tonerider don’t seem to specifically mention the bass humbuckers either. I sort of suspect that I can use one of the dual humbucker diagrams and just omit some of the wires, but I’m cautious because the kit description read that the pick guard was pre-wired and it’s not, and the diagrams I see often omit wiring that should already be in place.
I’m also unsure of whether I have to ground the bridge? There’s a hole leading to it from the control cavity, but I’ve seen some info in the past indicating that certain setups require it and certain setups don’t.
Any help for a relative newbie would be great. I’ve only wired one kit before, and that was on a course where I had a luthier walking me through the steps.