after removing all the solder i sanded all the corroded areas with fine sand paper to reveal the copper, i then cleaned with the 50/50 vinegar solution to neutralise any remaining acid. I then rinsed in warm water and cleaned with alcohol. I then tinned all the tracks & pads then de soldered all the solder from all the holes. cleaned with alcohol again and gave the top of the board a light coat of pcb lacquer (the type that is able to be soldered through) before i lacquered the board i masked all the plugs and empty I.C. sockets with masking tape as i do not want any lacquer on these as it will cause all types of trouble if theses are sealed