How do I find information on how to replace pickups on an active bass?

I have an Ibanez SR300E bass guitar which the pickups have died on and I need to fix it, problem is I live in regional Australia and there's only one guitar repair guy in town and he doesn't do electrics, so I'm up the proverbial creek unless I can figure out how to do this myself.

I have a basic understanding of how to solder, but I've never messed with guitars so I'm not sure what I would need to know before I start.

I've reached out to a couple of places to see if they're able to find parts, otherwise I might need to try to fix the broken pickups somehow.

Googling doesn't really get you very far these days so I was hoping you fine folks might be able to give me some pointers on where I can look for wiring diagrams or anything else I would need to know before I start opening it up.

(I'm not a professional musician by any stretch so I'm not expecting the guitar to sound amazing, I just need it to work)