Disconnect the negative battery cable.
Raise and support the vehicle safely.
SO IT DOESNT MOVE?
– Drive the front-right wheel up on the curb, so that you have more room to crawl underneath it. You could also use a jack and jackstands, or a hoist, as available, but the sidewalk is pretty much free, and everyone has one.
Label and disconnect the starter solenoid electrical connector.
LABEL ALL THE WIRES GOING IN TO IT?
– There should only be two wires. One big one (main power), and one small one (control). I wholeheartedly recommend against touching both contacts at the same time with an unprotected metal tool. Both of the electrical contacts should be held on with nuts.
Remove the mounting bolts from the starter motor, then carefully lower the assembly from the vehicle.
LOWER THE ASSEMBLY FROM THE VEHICLE? WHAT DOES THAT MEAN?
–The starter motor assembly. The part that looks the same as the part in the box you got from Napa. It’ll look kind of like… well, a starter motor. They call it an assembly to make themselves sound more professional/technical. It’s one of those things shops do to justify taking your money.
Install the starter motor assembly complete with any shims that may be used between the engine block and the starter.
WHAT ARE SHIMS?
– Flat pieces of metal that adjust the spacing between two components. Don’t worry about this, yours probably won’t have any. Just in case, though, if any flat pieces of metal were sitting between the starter and the bellhousing, transfer them over to the new starter. But as I said, I highly doubt you’ll have to deal with this.
Install and tighten the starter mounting bolts to 17 ft. lbs… (23 Nm).
17FT? IS THAT HOW TIGHT THE BOLTS ARE?
**-- That is the torque specification. 17 foot pounds is about how hard you’d need to twist to open a moderately difficult jar of salsa. It’s hard to explain, but just tighten them so that they’re “tight enough”. As firm as you can get them without feeling like you’re going to break something.
Connect the starter solenoid electrical connector.
Lower the vehicle and connect the negative battery cable.
The only tools you should need are a basic ratchet and socket set. If I had to guess, I’d say that the starter electric connectors are secured with 10mm and 8mm nuts (roughly 3/8" and 5/16" if you swing that way), and the mounting bolts would likely be 13mm (1/2"). Being a Geo, the fasteners are probably metric.
Oh, and even though every car manual will always tell you to disconnect the battery before doing pretty much anything, this is one of the times when you definitely should disconnect it. Even in a small car like yours, the starter probably draws 60 amps or something.