How do you fix too much freon in the air conditioner?

I'd go with the neighbors' suggestion , just so some mechanic in your area can make some money from somebody trying to save money only ending up spending 3 times as much by taking short cuts and guesses . HOW do you know there is TO MUCH R-134 in the system without at least a pressure guage??? unless the screwdriver has one built-in (that would be cool).

The proper way is to take it to a qualified shop that will connect it to a a/c refrigerant recovery machine. The system will evacuate the system and then it can be recharged to the exact proper charge. System will cool better and less chance of damage to compressor that you may exsperance if its over or under charged. We shops are mandated by the EPA to have the correct equipment so the refrigerant is not vented into the air. Lots of people want to save money and do it them self but are not equipped to know when it the correct charge and then end up doing damage many times.

I would recommend taking it to a shop, might even be illegal in your state to release freon into the air.