Can Apple remove an previous iCloud account that’s active on my iPhone 6 Plus?

I recently just bought an iPhone 6 Plus from a second hand person that owned it. The only issue the seller told me was that the iCloud is locked due to someone previous before her purchasing the phone had their iCloud account still set up. Now I’m wondering if Apple is willing to remove the iCloud account and I can use my own account to get access to the phone I purchased.