Nooo!! Don't do it yourself, I'm not sure which way round it is whether light to dark or dark to light, but don't do it yourself. My mum did this and ended up with green hair!! You need a base colour on first, red I think. But do listen to me, wait till a hairdressor comes on to help you. Just wait. I don't want you to end up with pink hair or something!!
Oh and my friend recently went from red to blonde - she now has orange hair!! Luckily she isn't too bothered by it, but it doean't look great. - xx