I am going to show you How to Change the Keyboard on Your Android Phone.
Some of the keyboard on Android have already a build in a key for this action. when you tap it will allow you to change the keyboard. I have here a globe key that if i press will allow me to select the keyboard.
Some keyboards like this do not have this. So how can you change it?
Go to Settings->General management -> Language and input
Here you will find the option for Default keyboard.. this will allow you to change it back how you wish.