Tell them what they're going to achieve from a business perspective by using the system correctly. They really won't care about what happens behind the wall.
When you go to eat a burger, do you really care about the way the meat processing is performed? Or the way the tomatoes are picked? You trust them to do it the right way, but you don't really want to know the gory details. What you want is to have a good burger, and they have to deliver. Same with IT.
Senior Management wants the ERP system to do stuff. You enable them. Show them how that happens on their terms, not yours.
This is scary shite.
"Ask not what A Group of Employees can do for you. But ask what can All Employees do for A Group of Employees." -- Mike Dennison