sticker

I found this scratch on my tank, I have no idea how it got there I noticed it after I had it parked outside a coffee shop for 30 mins not sure what caused it. Since it's pretty deep i was thinking i could perhaps cover it up with a sticker however i'm not sure what i should place in that...

So, how the heck do I remove the fuel warning sticker from the fuel tank without scratching the paintwork? Seems to be welded on.... Is it a case of getting the hairdryer on it first and then using Autoglym or something similar?

Hi Has anyone removed the sticker from the tank and if so did it leave any marks on the tank and also if you did remove it did you use any sort of label remover? Cheers