How to adjust string heigh on a Gibraltar standard-7 bridge

[Kinzoku]

Hello, i'd be very thankful if someone could enlighten me on how to adjust the string height on this type of bridge because i'm clueless and feel dumb

 

[isispelican]

twist the little screws that are right and left from each string

 

[Daf57]

^ this. They are 1.5mm - that size is usually included in most metric hex key clusters.