Q: Cheapest way to reinstall new airbags , driver and passenger ?

First of all, I hope that everyone was safe in the accident. Generally, you should not attempt to install an airbag until the complete system is checked. This is done using special airbag simulators and by checking for codes to see if there are problems in the system that will cause the new airbags to deploy as soon as they are connected and the battery is connected.

There are sensors in the car and a module for the airbag system that may need to be replaced also. As far as damage to the dash frame and dash panel, you will need to replace any bent or broken pieces. The steering column may also need to be replaced if it has been compressed and may bind if it got damaged. Only a trained professional should work on this system in order to prevent anyone from getting hurt, or causing the system to not work in the case of another accident.