Brake fluid is just the job, leave the model in say over-night and then use a toothbrush (either an old one, or failing that use your sisters!!) to scrub in all the little recess's and it will take off the paint just great, before you then try to respray it ensure you give it a damn good wash using warm soapy water, then rinse it and leave to dry 'cos i there's ANY trace of brake fluid left it'll mess up your new pant job and then you're gonna have to do it all over again!!