Replacing the gmail account on my Mi android phone My mother gave me her MI phone with android. It has her gmail account. I want to replace it with my gmail account. How can I do this?
I looked at Settings -> Accounts -> Google, but did not find there any way to replace the account.

Even better: is there a way to "format" the phone, so that I can start from a blank phone and directly enter my gmail account?
My phone is mi5 pro running MIUI 9.5 Android 7
In the settings menu go to Sync > scroll down > click add account > enter your Google account 

Step 2 is to delete the existing mothers account. Sync > Google > select moms account > gear icon on the bottom > remove account.