Given that half of your post rewards comes in the form of SBD and half of your rewards comes in the form of Steem Power, the question inevitably comes down to "how do I exchanges my SBD into STEEM?"
To that, there are several answers:
The simplest and most effective way is through the internal Steemit market. Go to your wallet, and click either on the drop down menus for Steem or Steem Dollars and click on 'Market'. You're given an internal platform that looks like a typical brokerage trading page. This reflects the ratio between Steem & SBD. If you're trying to buy Steem and want a market trade, click on the price of the lowest sell order & enter how much SBD you want to sell. Then execute the order and it should be taken right away. If not, keep setting the price higher. Likewise if you're trying to buy SBD. Just do the opposite and use the price on the buy order.
One can also convert their Steem Dollars using the built-in mechanism. What this does is converts 1 SBD for $1 USD worth of Steem for whatever the market price is after a 3-day waiting period. In a high-priced SBD environment (where SBD > $1 USD), utilizing this method rarely makes sense. Given that SBD is currently priced at more than $11, I would highly... highly NOT recommend to do this method unless you want to shaft yourself. This is most useful when Steem Dollar prices are < $1 USD.
Using an exchange service like Blocktrades is another way to accomplish this exchange, although it's a bit roundabout if you're trying to accomplish this task within Steemit. It makes more sense if you're moving from one to the other into another wallet outside of the Steemit ecosystem. Just go to wallet and click on "Buy Steem or Steem Power" and follow the directions.
Using a major exchange like Bittrex is another way of accomplishing this task. Simply register an account, send your funds to your account there, exchange your currency for whatever the available pairs are (usually BTC), and then exchange back into the other currency. This is the lease efficient of methods and can often be a bit costly given the number of fees tied to it. It's really only useful if you're trying to move in or out of the platform and for niche use cases.
Last of all, offline transfers made directly with peers or contacts is the low-tech option. It's insecure and inefficient, but obviously can be useful in any given circumstance should the conditions merit it.
