Passenger seat lock

[Noon]

I was wondering if anyone has experience/knowledge of how to replace driver side rear passenger back lock used to fold down the back. I've a '08/'09 Versa S hatchback and the hook to unlock the back needs to be replaced. I've the hook but seems like I'll have to go through the upholstery. I'm not sure about this part. Dealer quoted a price of $100 while the hook itself cost me $11. All suggestions will be appreciated.