Coke bottle in a row

You know the guy and his famous metal puzzles? You may also know his bottle puzzles I am sure.
But did you see so many bottles???

7 coke bottles linked with a long rod and locked on each side and inside!!

A lot of care is needed to handle that. First because it's fragile. Then because if you hold the puzzle on each side you apply pressure in the middle of the rod. It would be a pitty to destroy such a beauty:)

You can unlocked the 2 locks on each side, but how to unlock the inside locks?...

You don't have acces to them with your fingers....probably no tools are allowed....

Seriously I am (b)locked... :-(

Any idea?