I have dark brown hair and I'm thinking of going lighter?

I have dark brown hair and I want to go platinum blonde. I've been around to a few hair salons and they keep feeding me this bullshit about having the process done in a few sessions cos my hair might "burn". Hair is just hair, I don't give a ****. I just wanna get it light in one day. I know this is possible cos I've had my fringe dyed from black to silver and now it just seems like hairdressers want my money. Anybody recommend anything? DIY?