Being in the black is always a good idea, but it's doubly true as you approach retirement. You don't want costly debt when you're not working.
Pay off the credit card with the highest interest rate. Once that debt is wiped out, go for the card with the next-highest rate.
You could also move some of your high-interest credit card balances to a card with a lower interest rate. But read the fine print: Sometimes low-interest-rate offers are only in effect for short periods of time, after which the rate skyrockets.
What's more, consolidating your debt on one card may lower your credit score if your debt-to-available-credit ratio worsens.