As far as I know, there is no need to uninstall previous chapters. Episode 1 has the links to the five chapters already, but none of them are active yet except 1. When you download and install the next chapter, the in game link should start up episode 2 automatically. If someone with more knowledge of how the game works in this respect can back me up, that'd be great. I assume this is how it works, but I'm not sure.