Thanks For Choosing Just Answer!
Is the battery light flashing?
What was it doing prior to replacing the alternator? Was it just on or Flashing? Did they ever load test your Battery?
There are some troubleshooting Procedures. If the alternator was rebuilt I would have it re-checked. Sometimes re-built alternators can cause issues. Most likely you have a short to ground causing the light to stay on. Below is a link for some information on the battery light. I hope this helps.
That's good it is a new alternator, I would clean the grounds up, check your battery cables also, make sure they are clean and free of corrosion. Sometimes they will put what is called NCP on the terminals its basically a anticorrison inhibitor. So if it looks red I wouldn't mess with it. There is a test procedure in what I sent you, to tell if it is the alternator or the wiring for the indicator light, It is sounding like it is this wire.
This is going to take some troubleshooting on the wiring. There is no simple way to re-set the light, I wish there was. I know what you mean about the oil change deal with resetting that. You do have the information, and I would present this if you have the car worked on.