How to delete all files in Pictures folder after I moved all the pics to external HD I am not a Mac owner and am only helping a friend. He bought a new external HD and he wanted to backup all of his pictures (he uses iPhoto). So, I drag and dropped the Pictures folder onto the HD (formatted as HFS+). I'm assuming this also includes his iPhoto Library. I plan on option click open iPhotos and going into preferences to point to the external HD. 

However, once I point to the new iPhoto location, what is the easiest way to delete all files within his Pictures folder? Right now he has 370 GB of pictures on his 500 GB MacBook Pro and so needs to make space badly. Also, once the Library is pointed to the external. He will always have to have it connected when trying to import new pictures into his computer correct?

I know this might seem like a simple question but google wasn't as helpful as I thought it would be.
Firstly, yes he has to point to the external HD when trying to import new pictures into his computer.

Then you can easily delete Photos Library (see following pic) (usually located in: /Users/&lt;name of the user&gt;/Pictures) that package contains all the photos in the application Photos. At the end if he will proceed with emptying the Trash all the pics in the Mac will be deleted.



More precisely, you can do the same for iPhoto. The library name depends only to the application you are using. So for instance if instead of using Photos, your friend is using iPhoto the library you want to delete will be iPhoto Library!