Online Tutorial:
1. Shift rear derailleur (right shifter) to the smallest (fastest) gear.
2. Pick up rear end of bike by holding on to the seat and spin the cranks until the chain drops to the cog you shifted it to.
3. Disconnect V-Brakes by squeezing the brake arms together and pulling the cable noodle (silver curved pipe) out of the brake arm. (if it has disc brakes, skip step 3)
4. loosen rear quick release located at the rear hub.
5. Pull down on rear wheel and fish the chain outta the way.
(rear wheel should be off now)
6. Disconnect the front brake using the method in step 3.
7. Loosen the front quick release, then un-screw the nut far enough to remove front wheel from the fork.
8. Pull off the front wheel.
9. Loosen the seat tube binder (should be a quick release similar to the hubs)
10. Push the seat as far down as it will go.
This should get the bike in the car.
When re-installing the wheels...(if it has disc brakes) be sure to align the rotor in between the brake pads, as well as getting the chain on the last cog.
Don't forget to get your quick releases nice and snug so you don't die.