What screw head?
A security screw (tamper proof) probably a Torx head...
How to fit a new cord?
Don't even try - modern irons are not made to be repairable - you have to destroy an iron to access the workings - it's a safety thing and the manufacturers think it a fine idea.
Good Luck...
January 2017
Automatic Answer
While you wait for answers, we may have found some information which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix steam irons.