If your calls expire before the end of the year, just leave them be and they will expire. If they expire in the following year, you have a problem. Each day, you can try to sell them for a penny but the odds are slim that anyone is going to buy your worthless calls.
There is a way to get rid of them but it's going to cost you modestly. Find another call that is liquid and has a narrow bid/ask spread (the higher the strike price, the better). Execute a vertical spread order and then close the new leg. For example:
XYZ is $50. You own the Jan $60 call quoted at $0.00 x 0.05 . The Jan $50 call is $1.00 x 1.05. Place a combo order to buy the Jan $50/$60 vertical call spread for $1.05. If necessary bid $1.06 or $1.07, etc. If filled, you'll have sold your calls and bought the Jan $50 call.
Before placing the above order, open a ticket to sell the soon to be purchased Jan $50 calls. The moment you get a fill on the spread order, execute the second sell-to-close order at the market. All of this assumes that you get immediate execution notification. You'll have to monitor the position because you need to STC ASAP otherwise you'll add some market risk to the equation.
The cost to you will hopefully be no more than the B/A spread and if you're still paying commissions, three of them.