If the only thing you want to get rid of is them showing up in your reminder list:

Go into Company Preferences: Select Reminders tab on left: That shows a list of items you have the option to 'show summary', 'show list', and 'don't remind me'. I had 1,000+ sales orders to print in my reminder list that was making me crazy. I went into the list I just mentioned and clicked on 'don't remind me' for the sales orders. AND they're off my reminder list now!!! Yay!!!