Best way to Repaint (used figures bought on ebay ?)

[Hayabusa]

hello guys,

I was wondering what would be the best way to repaint (used PR toys/vilains)


Question

#1 which paint to use (would model paint (used for model car work?)

#2would i need to scrape the old paint on it?

Or just apply new one on the old one ...?


thanks in advance(btw i know my english sucks ) at least im trying!:P