ok, doesn't mater
sometimes it's good to read the help that comes with the app.
so here is the copy/paste for others like me:
To remove photos:
Select the album.
Select the photos you want to remove. (See Related Topics, below.)
Do one of the following:
To remove a photo from a regular album, press the Delete key. (This removes the photo only from that album, not other albums or your library.)
To move a photo from a regular album or Smart Album to the Trash, press
Command-Option-Delete. (This also removes the photo from the library and from every album, slideshow, and book where it appears.)