First off you want to go to this page
http://df.nexon.com/?GO=pr|godeventserver&ST=dnf&PS=bnoti&BN=2When you're on that page click the right button as shown here
After the pop-up comes. Click the top right tab as shown here.
After that you should see you character name on the left and a drop box of what server to transfer to. If you're going to Sicoro then you want to choose this: 시로코
Then press the button on the bottom and you are transferred.
P.S. Make sure you are not in guild or have anything in your mail box as it wont let you transfer till you do. And be offline as well.