Probably quicker and easier to sell and/or trade the 2021 SR 5H for a 5HH honestly. I don't believe the 5H bodies are routed for another pickup, so that would need to be done, and the wiring involves not just the switch but also the PCB. Then there's getting another pickup that matches the existing pickup correctly. You'd have to score one on reverb or ebay because EBMM doesn't sell pickups.