1) I vote for "serviced immediately". Be sure you follow the correct procedures to check the fluid-level: car on level ground; tranny hot; moving the shift level thru R, N, D, 1, 2, and finally P while your foot is firmly on the brake padel and the engine is running; check fluid level now. If you have to wipe the dip strick, use your finger and then clean your finger later.
2) You want to know "how this belt was ever put on (or off) in the first place", here is the way I do it. I will have to warn you that this method is dangerous if you do not do it right. You are on your own. I am not responsible for any damages or injury as a result of doing what I have been doing.
To remove a belt, put a big screw driver tip under the belt before the belt and the pulley meet. The tip of the screw driver sits against the pulley outer edge. Pry the belt a little so the the portion of the belt just before the pulley will line up with the outer edge of the pulley. Have a helper to "tap" the starter. The helper have to skillfully turn the key just enough to turn the engine a little but not enough to start the engine. Instead of using a screw driver, a better way to do this is to bent a hook at one end of a blazing rod. Put the hook under the belt before meeting the pulley and tilt the rod. There is a tool you can buy to put under the belt to archieve the same purpose. But I find the tool is not that effective.
To install the belt, I put the belt in the crank pulley first and then put as much as the belt allow over the "beginning side" of the steering pump pulley. Now use a big stick or screw driver pushing and holding the belt against the pulley. At the same time, have a help to "tap" the starter. I have to be careful now how I am standing. I do not want to lost balance and lost my screw driver once the steering pump start turning. The best way is to tap it in two or three small steps: if the first small tap, the belt catches the pulley and there is no need to pull it with a screw driver; the second or third tap will complete the installation.
In the case that I have to remove other belts in order to change just an A/C belt. It will be my judgement call if I should use these methods to remove/install other belts WITHOUT loosing any mounting/adjustment bolts. The decision is based on the condition of the other belts and the belt tension. Of course, if I break the belts, I have to pay for them.
As always, safety first!