It is very easy. Go to the "Main menu" – "Settings."
Tap the green button to the right from your name.

Special Menu will open. You can type the name you would like to have in the game in the insert area.

Your photo can be only downloaded from your Facebook account.

If you want to be represented in the game with a certain photo, put this photo as your avatar on your Facebook page.

Then run the game, enter the “Change name” menu and tap the“Load from Facebook” button.

Here is a short video instruction:

Good luck!