First step, go to www.skat.dk and press "LOG IN"
Second step, login with your NEM ID (if you own the company you can log in with your personal NEM ID).
Third step, this is not a real step, but is just in case you dont have your NEM ID, you can login with CVR and PASSWORD.
Fourth step, This is the page you will see after logging in.
Fifth step, Press "MOMS" in the top bar, on the left.
Sixt step, press "INDBERET MOMS", under the MOMS section.
Seventh step, the website will suggest you which MOMS report you need to do, so you select it pressing "INDBERET" to go further.
Eight step, a form will be shown to you, to be filled in.
Step nine, fill in the form if you have the informations, or just fill in the places where an * is shown.
Step number ten, and last one, press "godkend".