How to treat rust ?

The rust must be cleaned off on both sides, wire brush first then sandpaper till all the rust has gone.Buy a small tin of rust inhibitor and paint both sides,also purchase car body filler, read instructions and fill affected area,rub down with rough sandpaper then when it is looking OK,rub down with wet & dry sand paper,fill any small holes with filler then rub down till smooth.When dry paint with under coat, spray or paint,rub with wet and dry fine paper,spray or paint with under coat again,let dry then spray with tin of top coat twice or three times.  more