iCloud is a useful tool that lets you access a wide range of Apple services, store your data,

and protect it from hardware problems. However, you may have decided that you'd

rather sign out of it and store your data on your own. If so, just follow our instructions and you'll know what to do.

The Short Version 
Open the app for Settings. 

Tap your name at the top of the page. 
Scroll to the bottom of the page and click the "Sign Out" button. 

Type in your Apple password and make sure you want to do this.

Apple will ask you for your password, so do this.

Then you'll be asked if you still want to make the choice, so make sure this is what you want to do.