There are 2 ways to move the location of the pin. Firstly you need to click on the Pin icon bottom right of the hole overview to access the Green view.
1 - Click on the pin and drag the node to the new location on the green. After successfully moving the pin, the distances of your putts will be automatically recalculated.
You can also use the "nudge" feature. Once the pin is selected you can press on the + and - symbols bottom left on the hole overview to select your foot increment and then using the left, right, up and down arrows on your keyboard, you can nudge the pin to the desired location.