Old style photo album, how do I get the photos out?

In the early 1980's these photo albums were popular. You'd lift up the cellophane & place the photo on the sticky page beneath, then smooth the cellophane back down.
Now, I'd like to remove the photos from the album, but they are stuck pretty good & I don't want to damage them.
Would anyone know if there is a safe easy way to get the photos out?
I was thinking maybe heat, or cold might help... any thoughts?