Select Text Viewer in the screen that pops up, then click the edit button. Find the line that looks like root:UlGASB5XWDrOc:0:0::0:0:
The part we need to edit to change your devices password is between root: and the first :0
Next you want to generate a new password hash. You can do this with the perl function 'crypt'. If you've no idea what that is head over to Crypt Tool online . At that website you see a large text area with $str above it, and a one-line text input with $salt above it. $salt can be any two characters. In $str will be where you type your new password, go ahead and do that, and salt. Next click run.
You should get a result like what you previous hash was, it should be without any special characters.
Replace the text between root: and the first :0 with your generated hash. Be careful to copy it exactly.
Click the Save button at the top of iFile screen, then Click the Done button.