How to bypass a pass code in Ipad 2.

Hi there! I bought an Ipad 2 from online and when the product arrived, I feel a little depressed as it required me to enter a 4-digit passcode before I can access the unit. I tried, restoring the iPad through iTunes and it worked. However, when I try to activate it, I never succeed as it is still linked to the icloud account of previous owner. I try contacting him but he said, he forgot all the details he used when signing up to iCloud. Now my question is, is there any way I could restore the iPad without using the iCloud account it was linked to? I would really appreciate any help I could get from you guys. Thank you so much!!!!