Oilve/Yellow M-46? Are you doing one of those Korean War Tigers? At any rate, it sounds like a sticky wicket you've gotten yourself into. (sorry) Hopefully you're painting with enamel because it sticks better to plastic than acrylic. The trick here is to get something that will take out the adhesive while preserving the paint underneath.
Sometimes you can pull adhesive off by using more tape. The adhesive stuck on the surface of the tank might stick even better to tape than the tank. Go slowly and be very careful that you don't pull off the paint. A chip here or there can be retouched or be made to be part of weathering, whereas peeling of sheets of paint will mean a repaint and more aggravation.
If tape doesn't work, you'll need a gentle cleaner. There's some stuff that I have that is called Desolve-It. If you can't find that, I believe that the citrus cleaners sold at Home Depot are similar. In spite of the name, it is a fairly mild cleaner, being more oily than anything else. Of course, since enamels are oil based, I could envision it taking of the finish. I have never used it on a model before so I don't know whether or not it would damage the paint. Before trying it where it shows, do some experimentation on the underside of the tank where problems won't show and repainting is easy.
After that, keep experimenting with houshold cleaners( Dish Soap, Windex, Formula 409, Simple Green, etc) until you find something that cuts the tape's adhesive while not damaging the paint itself. Good luck!