In Breath of the Wild, instead of finding heart containers while exploring, you’ll instead find and complete shrines and turn every four spirit orbs you have into either a heart container or a stamina upgrade at the Temple of Time. This can also be done in a few other spots outside of the Temple of Time but this one is the easiest to locate.
If you have buyer’s remorse on your chosen upgrade, you’re not out of luck. We understand how great it is to have all of that extra stamina but sometimes we need some extra hearts so we can not get 1-shotted by a Lynel or something. For those trying out Hard Mode, hearts become pretty important unless you’re very good at dodging attacks.
Once you make it to Hateno Village, if you explore enough of the village, you’ll come across a statue. If you interact with the statue, it will start a sidequest that will allow you to sell one of your heart containers or stamina upgrades for 100 rupees. Once you do that, you’ll be able to buy a heart container or stamina upgrade for 120 rupees. It comes out to a 20 rupee fee to switch around your upgrades. You can use this statue as many times as you want.
Check your map and you’ll find the statue north of Firly Pond. The statue is sort of in the middle of nowhere so it should be problem to find once you get in the right location.
If you plan on pursuing the Master Sword, you’ll need 13 heart containers so you may be spending some time with this lonely statue in the future. It’s important to note that you can get your 13 hearts for the Master Sword and then come back to turn them back to stamina once you obtain the sword. You won’t magically lose the ability to wield the sword if you do this.