These tuning pins have an extra-large hole to allow you to use thicker strings (larger than 0.047″) without needing to unwrap the winding first. Swapping is as simple as using your tuning key to remove the existing pin and then to screw in the new one.
Warning: These are slightly longer than some older Chernihiv factory tuning pins. If they are longer than yours, you should make sure to leave a few threads visible when screwing it in! If you screw it in all the way, the pin might hit the bottom and eat up the tuning hole, causing it to no longer hold as strongly as it should.