How do I change levels in Scrabble

On getting to the first screen, click on the new game icon. When you get to the next screen click on the continue button, this will take you through to a third screen. On the left hand side there is a grey tile with the number 2 on it. Click on the number 2 and this will highlight it yellow. On the right hand side of the screen there is a tile that says computer, which is also highlighted yellow. Now click on this. You are now into the level screen. On the right hand side there and + and - tiles, click on these to change levels.