It's not really that hard, just fiddly. Get yourself some butt connectors and crimpers, snip the wire, reconnect. There's not really a ton of slack, so it's probably easier to do what I did and just use an extension wire and 4 butt connectors instead of two. All that button does is complete a circuit (or interrupt one), so it's not exactly a super-electrical-technical thing.
One thing I did that I think made it easier- while pulling the wires up through the shifter lever, make sure the two white wires pull the black insulation/ covering with. Use tweezers to get that to pull out too if you need to. THAT WAY, when you go to push those wires back down through, its less like pushing rope and more like pushing a cable with some stiffness. I taped the white ends down with electrical tape at the end of the black insulation, and it went through pretty easy.
I'm having trouble in the last stretch though- it's all back in and working good, but I can't for the life of me get the shifter knob to properly seat back up where the button works as intended and the screws in front go back. Any pointers there from the crowd? Right now I have to do a little wigglin and fiddlin to get truck in gear or back into park.