Thanks for your replies.
I'm just starting to get acquainted with the truss rod. Without loosening any strings, and just trying to insert the wrench in the truss rod hole, it seemed to be slack.
I want to try and lower the action a bit. To do that, I should turn the wrench to the right, I think.
I think I should loosen the 3rd and 4th strings to give the wrench room to move. Then I should turn the wrench to the right in small movements.
Does this sound like the right way to go with you?
Would you agree with what I've said so far