This is the Rolex issued booklet that comes with their bracelet sizing kit. It covers everything you're likely to need to know about adjusting bracelets and in particular, the correct screwdriver size.
Chekout the bacelet code and look it up in the booklet. Follow the instructions especially regarding loctite.
It's important to use the right bit size. Too small and you can quite easily mess up the head -- too big, and you'll damage the links.
A hollow ground bit is the easiest and safest type.
https://www.minus4plus6.com/images/R...ng_Booklet.pdf
Edit - if that exact bracelet isn't in the booklet, best to measure the screwhead as accurately as you can with calipers.