iPad mini currently link to an Apple ID of the first owner ,to set up my second hand iPad.

I Brough a second hand Apple iPad mini , viersion iOS 6.0.3

i restore the iPad but , still linked to an Apple ID of the first owner so that I can set up the iPad, I don't even know who was the first owner of this iPad mini,. How i need to delete the iCloud account of the first owner , I tried to connect to my laptop through iCloud but still not working.. Please help me solve my problem . Thank you, I My daughter need this iPad she went to nursing school.. Hoping for your kind consideration,