Inserting the battery into the ZOVII - ZCL08 - 120:
Use the unbrako provided to loosen the screw inside the actual "locking opening". This is a 2.5mm screw.
Then use the Allen key to gently push the yellow plastic part so that the actual top cover of the lock comes out.
On this top cover there is a black rubber cover (can be a little difficult to detect right away) the size of the battery that you remove. This is where the battery should stand.
Finally, you assemble everything again!