Minng is carried out automatically from the surface to the depth of the drill head. To start, land on a relatively flat surface such as a lake and press # 6 on the # 1 digital pad. By default, the process will go 25% filling the cargo volume. If you need more, find in the control panel PBL Code and change it's CustomData string (max 100): Run PBL Cruise = mining 25

You can also watch the video https://www.youtube.com/watch?v=Z17k6wQItBM at 8:35

how do i use the drills?