Hive account@jaraumoses recently made apost about this. That time it was changelly but unfortunately it nolonger changes to btc. So we found a better alternative which is blocktrades.us it takes less fees and quite abit fast. It will ask for your bitcoin wallet so you must have initiated a request in your bitcoin wallet. This is basically what it takes to change SBD to BTC, other wise there other site you can use to change to btc but i have used blocktrades and it worked for me, it will work for you too.

Soon i shall make a post about this using blocktrades.