Hair talk

So I want to get this developer from sallys to lift my dyed black hair to get to reddish brown. I'm just a little confused on the process though. So do I put the developer on my hair and wait for it to lighten and then wash it out and the dry it and apply the dye I want to use? Can someone tell me step but step what exactly I'm suppose to do? I need help lol. I'm not sure even what to buy from sallys.