You can use a mixing service that swaps your coins for others with no history. Any of the following four services are reliable.
Unijoin.io is one of the best bitcoin mixers out there, for good reasons.
Bitmix.biz is a reliable offline bitcoin mixer that takes your privacy seriously.
Blender.io is another top offline bitcoin mixer that allows users to send and receive bitcoins without giving away their identity.
The last thing you want is to be caught mixing your bitcoins with someone else.