Here's how I removed the original graphics. Lightly sand to remove the clear coat. A fine sanding sponge can work well for this, but takes a while. Use some Acetone to soften up the graphic, and lightly scrape it off. Some final sanding will likely be required. Beware, it's not really possible to take off the graphic without removing some of the base paint. You'll have to match and paint prior to adding new graphics.
Look for completed photos next week. I added some detail to the cockpit along with a "Best Pilots" Bob Sweeney figure. I'll do some work to the panel lines, add some weathering, and make my own nomenclature graphics using the pulsar Pro FX dry transfer system.