How do these chips wire in and where do I mount it?
They simply replace the points and condenser. MegaFire is a popular one these days, but they're all pretty much the same. Typically $12~$15 US.No idea if you use the single or twin terminal one but I have heard others talk about Nova.
Dual terminals are highly recommended so you aren't relying on the chip housing as the ground and so you can swap leads (change polarity) if necessary. Dual leads also allow for locating the the chip anywhere with RTV instead of requiring hardware and a location that will accommodate hard mounting. Plenty of wire is usually included to put em anywhere, but they are susceptible to excessive heat and should be located accordingly.
On the other hand, if you get the points right, (or replace em), that spark will stand up and bark. Sounds like spark may be the least of the saw's problems, though. I'd just pull it down and see what ya have. Some seals and rings may be all it needs to get a lot more out of whatever you decide on the ignition.