How can I separate these stainless steel pots?

try some oil to see if you can loosen them. Or maybe put it in a sink with hot water.

Heat bottem pan briefly on stove and quickly separate before top pan expands too! Might work!

Spray some WD40 along the seams and let it soak in. Place ice cubes in the top pan and submerge the bottom pan in hot water.

Hi, Twiggy!

If you have room, put them in your freezer. They will contract and should come apart... I hope this helps!

Place the bottom pan in hot hot water almost to the top. Fill the top pan with ice water. The bottom will expand while the top pan contracts. Should come apart easily. Good luck!

Set the bottom pan in HOT water. When it has heated, pour ice cubes into the top pan. Likely they will pull apart, then. :)

Thx's for the suggestions I will try them

Baxter and Twigg's suggestions are just what I was going to recommend. Bet it will work!

Yes there still stuck so I will try this suggestion Thank You

Crafty little Gnome: Your suggestion I used Vegetable Oil & let it set for a little bit & then in soaked in very warm water. Betsy: then carefully moved back & forth came apart. Thx You for all your ideas Glad I am on this site.

Let both pans run under the hot water for about 3 minutes the metel will expand and they will come apart

Try to slow heat the bottom one. Either hot water (best) or directly on a low heat element on your stovetop.

Put ice cubes and ice water in top pot and dip the bottom pan in a frying pan or other large pan full of boiling water. The top pan should lift out easily

Hot water

Here's a post that might help https://chascrazycreations.com/homemade-cleaner-for-stainless-steel/