First of all you need good quality scans of all the pages. Then take it to a professional conservator for advice.

Generally the only option for heavily glued photos is to split the actual pages down the middle with a scalpel and then remove the page from the photo, rather than the photo from the page!

It may be a better idea to scan the images, store the old album in a protective box, print the digital files and then sort the new prints.

Good luck.