Provided the new pickup fits the cavity correctly, here's what I've done for similar installations on several SCPBs.
Loosen the strings and tape them out of the way. Remove the control plate, desolder the pickup wires, remove the pickup, install the new pickup, solder the wires to the pot on the control plate, reinstall the control plate, un-tape and tune the strings, adjust the pickup.
"It's a Crapshoot." The timbre is in the timber. It's a poor craftsman that blames his tools.