[xeroinfinity]

Almost sounds like the passlock was acting up but maybe not since it started right back up.

Get a voltmeter and test your battery.
Should be around 12-13 volts with the car off.
When the car is running it should be 14+volts.

And yes its pretty easy to replace the alternator with a few hand tools.
If you have to replace it here are some directions.

- First disconnect the batery.
- A 3/8 ratchet will be needed to loosen the belt tensioner.
- Unscrew the power wire(red) and unplug the harness.
- I think thiers 3 bolts holding it on. 1 in front 1 on the side and 1 in back.