Best way to remove spray paint?

[Tradermon]

So I'm making a red Marth themed Gamecube controller and I messed up on the back yesterday. I didn't apply the paint correctly on the back side so it came out looking weird, like paint was just spilled on it. I was dumb and thought that extra coats would fix it but NOPE. So now I'm trying to remove it to paint back on, but I don't know how that wouldn't require a ton of sand paper and time. I had a similar issue happen tonight with the front (where masking tape was misplaced after a day of drying so I thought respraying a little paint would fix it but it created horrendous wrinkles), and I was kinda able to get most of the paint off, but I'm worried about repainting because I'm worried that it won't come out well.

any thoughts???