do you really feel the need to sell your bitcoin anonymously or you just want to know it for the knowledge. yes for sure you can sell your bitcoin anonymously. you can use bitmixer exchange for that.
Bitmixer exchange... Even if you managed to mix the coins, it will still be traceable if these services gives up your identity to the authorities.. some of them are even collecting
information for these authorities, if you believe all the conspiracy theories going around.
If you are saying "getting rid" of Bitcoin, it sounds as if you stuck with something
you cannot use.. if you want to get rid of it, just sell it to someone on Localbitcoin, and hopefully that person is not an agent.