Remove the bread from the oven and place the molds on a rack. I wasn't sure if the recipe called for just mashed potatoes or mashed potatoes finished with milk, butter, etc. It works great in a bread machine: use the DOUGH cycle, don't bake it in the bread machine, bake it in your oven. I'll try to improve the recipe and add more notes for future bread makers, but overall it's a very easy recipe that always comes out great.
While the bread is still hot in the pan, use a blunt kitchen knife and run it around the edges of the pan, between the pan and the bread to release the breads from the pan. But I haven't found freshly baked potato bread in the market yet, and making it at home is easy, especially if you have a mixer or a bread machine. This homemade potato bread is an old publication that has recently been updated with more detailed instructions and helpful tips. If the mashed potatoes are well seasoned, it's best to reduce the amount of salt in the recipe.
With all the artisanal breads available in the markets today, it's surprising that someone would make their own bread. My original potato bread recipe said that you could form 2 small loaves out of the dough instead of 1 big one. It's a pretty forgiving recipe, and in my experience, the amount of potatoes shouldn't be the problem. I just made this bread, followed the recipe to the letter and now it's sitting like a big lump in a bowl.