Yiorgo, the corners are a simple remove and replace... get a good flashlight and locate the three screw that hold them in place.
The first two will be easy to find.. the third one will take a bit more searching... notice that four inch piece sticking off the end of your corner? well place the corner next to your fender and envision where the screw would be for that one... you may need a short scrwwdriver to make things easier
kali tihi!