To get started, start from your homepage.

Select Wallet tab or "Wallet"

Next to "STEEM DOLLARS" for PC users and below for smartphone users, click the small triangle symbol around your $ amount

Then Select "Convert to Steem" from the options menu

There will be a waiting time. It takes three and a half days for Steemit to convert SBD to SP. After the SBD is completed entirely converted to Steem, the total amount converted will appear under "STEEM"

Now (example as in this tutorial) 20 of your SBDs have been converted to 18.52 Steem and you have 0 SBD left in your Wallet.