Remove tutorial video from the Affiliate panel

If you want to remove the tutorial video button from Quick navigation icons of Affiliate panel's Home page, you would need to edit the home.tpl template file.
You would find it at Configuration > Design > Affiliate panel theme > click "Edit theme" on the currently active theme > and look up home.tpl
Click the 'home.tpl' and you will see its code on the right side. From its code remove:
{widget id="Tutorial"}