Conversion of Steem/SBD
It's very simple.
Login to your Steemit wall.
Click on your wallet.
Click on the Cryptocurrency you want to convert into and choose "buy"
Example :
I have five steem and 20SBD and I want to get Steem Power with steem.
I'll just go-to my Steemit wallet and click on my steem, choose 'buy'option, which would therefore direct me to block trade website where I would select the number of SBD I wish to convert to steem.
After few minutes of reloading my Steemit wallet, my steem balance would have been credited with conversion amount.
I hope my answer is comprehensive enough
Best regards!