Years ago I learned that my mother in-law bought a timeshare years ago in Daytona Beach. She kept making the payments but never used it. Did you inherit or no longer want to own the timeshare you bought years ago, here are a few things to try to liquidate it:
First contact the timeshare company and ask if they have a program to surrender or take the deed back on the timeshare. Most of the larger companies have a program for taking time shares back. You may not get any of your money back using these programs, but at least you won't have to keep making the payments for a timeshare you are not longer using. If you are dealing with a smaller developer or resorts, they may not have a program which means you may need to resort to more aggressive options.
Stop making your payments. Before you do this you should understand the risks. It's possible that the timeshare company will report you to the credit bureaus for not making a payment. They may also bring a law suit against you for the non payments. In some cases once you stop payments, the timeshare company will let you surrender the deed so that they can resell the timeshare. This can be much less expensive then for them to go through a foreclosure.
Resell your timeshare to someone else. Again you probably won't get your money back from the original purchase but at least you will no longer be required to make the yearly payment.
Don't use a company that "Specializes" in helping you get out of timeshares. Many of these require you to pay up front and don't deliver results.