There are many factors which needs to be known to answer this question. We need your physical location, that is in which country you are. This can help in identifying the right wallet fro you which is able to do this conversion for you in your local jurisdiction. This is important because not all the wallets will give you permission to do so as long as they are not abiding to the local laws. If you want to skip this step then I would recommend you to go for localbitcoins which is the best option to do p2p transaction. Easy.