How to reapply self tanner when current spray tan begins to fade?

So I got a spray tan on Friday and now it’s beginning to fade and I know in a day or so it will start to become patchy but Wednesday I have a pool party. How do I go about applying self tanner on top without it looking like patchy? Should I use a gradual self tanner, should I just completely remover my tan as best as I can and apply self tanner, or should I just go in with self tanner overtop of it?