repainting a model question

 Hi there  fellow modelers

    I have a small painting problem, I was trying to add another coat of mm glossy white on my model which is a dash 8 commuter airliner, anyway I was airbrushing it on using the ratio that was on the airbrush instructions when it started to run a tiny bit then it started to act up more, so dumy me I thought I could wrip it off then I see stains on the model from handling it since I do not have any gloves, then it really got worst, the question Im asking is, would it possiable to start over and how do I start over or can it be repainted also I forgot to mention only the bottom of the model was affected the top I think except for a couple of tiny stains, can that be taken of also or  should I redo the whole model or just repaint the bottom any help would be appreciated-thank you.

                                Ronald