How do I remove Upgrade spin - back to original ?

There are various spin upgrade levels meaning that once the you tap the upgrade button to upgrade the wheel, you can do so again to upgrade to an even better wheel. The upgrade wheels are: Super, Mega and Ultra. Each has its own Diamond cost: Super - 10 Diamonds, Mega - 20 Diamonds, Ultra - 30 Diamonds. If the you spin an upgraded wheel, then when you next enter the wheel, it will default to the same upgrade level that was previously spun.

Once you've reached the Ultra wheel, the upgrade button will change to a Reset button, and allow you to return to your original Standard wheel. If at any point you wish to downgrade your wheel to standard, just keep hitting upgrade until you see the reset button.

https://scopely.helpshift.com/a/wheel-of-fortune/?p=ios&s=spin-upgrade&f=spin-upgrade&l=en