I am having some difficulties selecting an extration head after it got placed on a storage unit. How do I move the extrator head? The game keeps trying to select the facility and the only solution I found is to destroy the building to free the head.
Try very slowly to come from different directions with the mouse until the arrows appear. Just when they appear click and move the head.
But sometimes this is not possible. If your extractor does have some unused heads, just deactivate this head and activate another. That head will be placed somewhere else and might be accessible.