If it's a consumer-grade (non-refillable, non-serviceable, use once) that is your personal property, just buy a new one, and discharge and dispose of this one if it concerns you. Be aware that it will make a mess when discharged, so choose an appropriate location for that. You can enlist the aid of your local fire department as suggested in comments, but the slight overpressure (or misreading gauge) will solve itself as soon as you discharge it. If it's serviceable, same, but then get it serviced & refilled. Note that you cannot "partly discharge it" to relieve the excess pressure and then return it to service - the valves won't seal without a full servicing, and it will leak down to uselessness (as well as not having its full rated charge.)
If it's the responsibility of or owned by the apartment building/complex, ask them to get it dealt with. It's their responsibility, not yours.
To the best of my recall typical extinguisher pressure vessel test pressures are at least twice the operating/service pressure, so "near the start of the red" is not anywhere near "about to explode."