Wrong itunes account when updating apps
Once you have the password, follow these steps to remove the Apple ID account from i Cloud and Find My Friends: When signed out you can tap Sign In and enter your Apple ID and password to start using the device.
To learn more about the Family Sharing, you can read the official tutorial from Apple.
When you download or update apps it will ask you for your password.
Note that the app installed by the other person remains on your device.
Removing the rogue Apple ID from i Cloud or Find My Friends is trickier.
In these instances, Apple requests the password from you before removing the account.
You'll need to turn off the i Pad or i Phone, then plug it in to a Mac or PC with i Tunes installed on it (and open) on it while holding down the home button.