Need a Password to Update Apps!

my friend gave me this phone before and i delete anything here and put my gmail and new apple id. And i can UPDATE APPS Without Putting A PASSWORD But When It Comes For Updating My Messenger It Pop-up The iTune Apple Id of my friend and need to put the password before i can update my messenger. The saddest part also is she forgot her password in that Id. Guys! Help me plsss. Thank You.