I have a backup of a wallet.dat file I created and used about a year ago. I'm struggling to find a client which allows me to import the wallet as I've since got a new computer. Is it not as simple as finding a client and importing. I would like to use the bitcoins to pay for something.
If you are on your desktop then click Go at the top then Go To Folder you should be able to type ~/library
in there you should then see Application Support Inside of there you will see the Bitcoin folder with your wallet.dat inside of it. replace that wallet.dat with the one you want imported and restart Bitcoin