Start by ensuring you are using a BIC mini lighter (J5 / J25).
Remove the sticker on the lighter and ensure that all the residual adhesive is cleaned off as well.
Insert the BIC mini lighter into the casing.
Make sure the lighter is oriented in the right way, with the sparkwheel and fork facing the same way as the opening of the casing.
Insert the grub screw into countersunk hole and fasten with the provided hex key. This will properly secure BIC mini lighter in the casing.
Unfasten grub screw with the provided hex key. Next, insert hex key through the bottom opening of the case to eject the BIC Lighter.