I have made a complete hash of iPhoto, succeeding in corrupting a lot of the picture files and getting the grey square of doom on many of them.
Fortunately I still have most of the pictures on SD cards and/or CD's.
I have wasted a lot of time recently trying to solve the problem to no avail.
I now want to delete everything to the original "out of the box" empty state so that I can start again.
Can you help. please?
I am clearly almost computer illiterate so would appreciate very simple instructions!

Thank you