It's a bigger job than you think it is. It isn't that it is impossible, but it is very involved. I'd say do at least a couple of top side tear downs on different games first. Be very familiar with soldering (and have a good iron). Be used to pulling apart pop bumpers. The time to take on a playfield swap is after you know how to disassemble and assemble the individual parts.

And after you take those, take more, from every possible angle. Digital pictures are free, and you will run into that small spot where the extra pictures will save your bacon getting it back together.

And two very important ones. 1. Don't assume any divots for drilling are in the right spots. You may find some of them are not exact on the new playfield. 2. Do NOT assume that the last person that put your game together did it correctly. If there are two (or more) hex spacers or ramp stand offs in the game, really check if they were put back into the correct spots by whoever had the game apart last. You would be surprised how many wonky ball hangups or strange ramp behavior come down to a minor difference in post side.

And if you take it on, enjoy the project. Don't do it just to save money, do it for the fun.