How do I repalce the motherboard for my gigabyte P34G-CF1

My gigabyte P34G-CF1 over heats, will not charge the battery and now will not run with the ac plugged in. I believe this is due to the connection on the motherboard. Sent it for repair and was returned in the same condition. So want to attemot replacing the mother board. do you have instructions on how to do this?