Work with your listing agent/broker. It depends on what phase you are in, past option period, could be you refund any expense of buyer, sign amendment you cant be sued. If you are contractual obligated the buyer could come back and sue. http://www.lynn911.comhttp://www.homes-for-sale-dallas.com
If you are locked into a purchase and sales agreement you should check with your attorney to see what exact ways you can get out. the two common ways are when the buyer has the home inspection, if they find anything wrong and ask you to fix and you refuse, however the buyer still has the right to say they will take it as is. so definately seek your attorneys advise to avoid getting sued. good luck
You need to look at your listing agreement and see what the cancellation fee is, if any. Usually a reputable company will understand your decision and let you out of that agreement. They want your business at a later date and to have a client that is upset is not good PR. Call the broker at the agency you have the listing and inform him of your decision and I am sure he will work with you.