If you acquire an AK, one tool you’re absolutely going to need is a Windage and Elevation Sight Tool. The other option is to take a mallet and a punch and start banging on the pin that moves the post laterally but this is not recommended! This C-clamp style tool is old school Soviet technology but it works. Tapco has a decent one for about $16.
There are other versions available but unless you plan on making this adjustment on a weekly basis (which you won’t) the Tapco unit is adequate. The pin on the front sight is usually very tight (as it must be) and takes some trial and error to get it just right. If you ever end up changing your rear sight, you’ll probably have to go through this process once again. Note that there’s also a notch on the screw (just above the handle or “T” bar that is used to adjust the elevation on the sight post).
This video does a good job of showing how the task is done.