I don't really know the answer to your question but I can "surmise" about it.
I splurge now and then and buy something I've been reading about that's intriguing. Usually I buy whatever is normally out of my reach and I like whatever it is. A year or two ago though, I bought some Mission Gold but for some reason, I don't (or at least I didn't then) like it. I had gotten the big palette to put those paints in, too. I painted with it a time or two. Then I lost interest and put the big palette away and didn't use Mission 'Gold anymore. I shared with my daughter and then, because watercolor goes such a long way with such a small amount of paint, I kept the almost empty tubes, knowing there were several other projects someone could make with the "dregs" of the tubes.
Well, as it turned out my daughter and HER daughter fell in love with those paints. Cutting open those tubes that were flattened did make it possible to use the rest of what was in them and by opening the flat tubes, there was paint my daughter could use. You just stir it up good and it becomes perfectly good paint. Even if it has separated and/or dried, they could use it. My grand-daughter tried to get my daughter to let her have some more but my daughter likes it so well she wouldn't share anymore of it.
Guess what happened next---I know this is a long, not-very-helpful post, but I'm very happy with the ending so I'll share that, too. I opened the palette to just see what I might have gotten it for and lo and behold----it was full of Mission Gold I had put away! The full set of 36 colors and I had even swatched them! My grand-daughter's fiance was killed in a car accident last July and she's been so devastated. We live in the mountains and the road isn't safe in winter so I didn't have the family come up for Christmas so I immediately texted my grand-daughter what I'd found and told her "Merry Late Christmas!" She cried! She was so, so excited. She had just told me a few weeks ago that she treasured those paints that her mom had shared with her and she didn't use them much because she's now raising her little girl alone and trying to get her hair salon up and going so she can't buy any more. I now have a better income than I did back when I splurged on those paints and I was so very pleased to be able to give those to her!
But back to your question, I'd just stir the paints with a toothpick or wooden skewer or something and go ahead and use it. Keep the tubes upright I'd guess. You could also just squeeze the tubes with the lid on and squooshing the tubes for awhile with the lid on would help mix the liquid back in. Good luck with it and if it's working, let the forum know because others can be helped by it.