In the "Help" menu of your wallet you'll find an option for "Debug Window".
Choose that option, and the Debug Window will open up.
In the Debug Window, you'll see a tab for "Console".
Choose that tab.
There will be a place at the bottom of the console where you can enter commands.
If you have not created a password for your wallet, then you can enter this command:
dumpprivkey theBitcoinAddressWhereYouGotPaid
Replacing the
theBitcoinAddressWhereYouGotPaid with the actual bitcoin address that you had the payment sent to.
You should receive a string of 51 or 52 letters and numbers that starts with one of the following (5, L, or K).
This is the private key for your address.
DO NOT SHARE THIS WITH ANYONE. If anyone discovers this private key, they can take all of the bitcoins that you received at that address, and will be able to continue to take any bitcoins that you ever receive at that address again in the future.
Once you have your Private Key, you can choose some other wallet that does not need synchronization, and that allows importing of private keys. Then you can import that private key into the new wallet and your bitcoins will be available to spend in the new wallet. The method of importing will depend on which wallet you choose, so we can't help you with that until you've chosen your new wallet.
You could choose a wallet that does not allow you to import private keys. If you want to do that, then you can set up a temporary wallet at blockchain.info, import the private key there, and immediately send the bitcoins from the temporary blockchain.info wallet to an address in the new wallet that you've chosen.
If your current wallet has a password, then before you run the dumpprivkey command you'll need to unlock the wallet with the following command:
walletpassphrase yourWalletPassWord seconds
Replacing the
yourWalletPassWord with the password that you used to protect your wallet and replacing
seconds with the number of seconds that you want the wallet to remain unlocked.
For example, if you used a password of
fheaodienes and you want to unlock the wallet for
30 seconds then you would type:
walletpassphrase fheaodienes 30