How is it possible to sell internet domain names?

You need not bother about ICANN to sell a domain..If you want to sell a domain....one should learn to price it. Many sellers fail to sell names in the marketplace, simply because they overprice the domain, and thereby loose the chance to sell it.Before selling any domain I advice you to appraise the domain to collect its market value.It will give you a rough idea about the range of the domain and hence will serve as a guidance in fixing the selling price.You need not spend to appraise your domain.I found a free domain appraisal service from Tucktail.com , so fix your price accordingly.
Once the price is fixed you can find auction places like eBay, Sedo, etc. Find a legit buyer and sell the domain.The domain registrant details need to transferred to the name of the buyer...this will be taken care of the domain registrar in most cases.
All the best for your sale!!!