You have just added a NATO strap to your collection and would like to put it on your William L. 1985 watch? First check that you have received the additional spring bars and then follow the instructions below.
Install the spring bars with a spring bar tool or a small screwdriver like the ones used to adjust eyeglasses
Once installed, you can now put on you NATO strap
First, remove the long end from the keeper
Then, slide the strap downward through the two spring bars
Take the long end again and slide it through the keeper
You can now fasten the strap as you normally would and finally tuck the tail inward or outward (your choice)