[un-merge 2 images? I think....]

Thanks Callum, and thats what I've just been told after also posting on the FB page, I've since located the History and gone from there...re-doing the post adjustments is a bit of a pain, but its done now, thanks for the reply,.

[un-merge 2 images? I think....]

Hi all, first time on the forum and total new comer to any type of photo editing, but I'm slowly learning...

Im having a play about on AP, making a door sign for my daughters bedroom, all has been going fine until somehow i have merged 2 layers (a background image and also an image of our dog standing up) into 1 layer?... i don't know how i done it but i can't for the lack of trying separate them again?  If anyone can advise please... Thanks