1 Copy your public receiving addresses from Bitcoin-Qt.
2 Go to the Bitcoin-Qt console: click Help/Debug Window and then select the Console tab.
3 Run walletpassphrase [your password] [timeout in seconds] to unlock your password protected wallet.
4 Run dumpprivkey [Receiving Bitcoin Address] for each receiving address to be migrated to MultiBit. There may be hidden private change addresses in Bitcoin-Qt which don't show up in the receive tab. Run listaddressgroupings.
http://bitcoin.stackexchange.com/a/13303 (Bitcoin-Qt -> BitShares-PTS 1.0):