I'm pretty sure they will require him to surrender an out-of-state DL for an in-state DL. I don't know about state ID's, though.

I do know that there's something in the traffic code requiring drivers to obtain CO DL's immediately upon becoming residents. I don't think that provision excludes students, so much as it says that students who don't plan on becoming residents are not residents.

As for time periods...I moved here on 8-29 of my first year here, got my DL on 8-30 of that year, and bought my first handgun from a dealer on 9-3. There's no waiting period like there is for resident tuition or resident fishing licenses.