They're most likely a 'pin and barrell' style (no arrows visible inside bracelet) these can be pretty fidely, if you've got the tools & have experience with 'split pin' adjustments (widely used in cheaper watches but also in some TAG F1s) it's very similar, probably some youtube videos out there, but otherwise I'd say try a watchmaker, shouldn't charge much maybe £10, and they can adjust whilst you wait.
Also I think some ADs do free link adjustments regardless of watch age if you have the gtee stamped by them?
