Second, depending on the photos, you may be able to get them apart by soaking them in warm (not hot) water. Try with only a few first to be sure that this doesn’t harm them. Let them “swim” for a minute or two, then see if you can gently separate them (be careful not to damage). If you can’t, let them soak for a few more minutes and repeat. When they are apart, lay them on paper towels face up to dry.
Another suggestion is to trim down the photos, if possible, to remove the areas that are stuck together.
However, if they are very old or really meaningful to you, you should take them to a photo shop or call a museum in your area for some suggestions.
The best tip is that I roll up scarves around the tubes, so that they are displayed in a drawer or on a shelf without wrinkles or creases. I can compact literally dozens of scarves that way, yet they’re handy to pick which one I want on the run.