Welcome to NICO Club! A sticker or square paper won't cause any issues with the stuff under the dash. The only worry I'd have is getting a ticket for parking! As long as you don't need the sticker, then you don't need to remove it in my humble opinion. To get the sticker, you may have to remove the dash, but you could spend some time with a flashlight looking up from underneath to see if you can grab it somehow. I would not pay a shop for this work. I'd leave it if I couldn't get it myself.