a lot of the the gauges cant be opened without breaking them because they are poorly made and use glue to close up the plastic rather than screws... if it is a glued up plastic one and there are no screws it is possible to crack open the gauge. There is usually a seem around the face of the dial that you could jimmy open with a razor blade of some sort... the likely hood that it doesn't crack though is slim in my experience.
another option might be to drill a small hole above the paper and carefully glue it down maybe get some glue on a toothpick and press it down with clean toothpick. Kinda like playing operation without the funny bone and red buzzing nose.
This is all based on the premise that we are talking about the same thing so get that picture up when you can : )