Q: Wifi: hardware not installed

I have a MacBook Pro that I bought in 2012 and beginning to have connectivity issues with the wifi. May I add that at random times it may work however less and less often has it been working. Sometimes I would turn the Bluetooth on then back off and restart the computer and it would work. Or I flipped over the computer, pulled out the battery plug from the circuit for about a minute or two then put it back and when I turned it on it would work. It seems to have more luck with different wifi networks than with my own also. I ran a hardware test and there was no error. Is there anyway I can fix it without spending $80 for someone to fix it. I live out of the states so quality labor can be expensive.