How do I change the installation file path for Starcraft 2 on my iMac?

I have an iMac. I tried installing Strarcraft 2 on it but being a life long PC owner i tried installing it to the "system" folder and not the "applications" now every time I run the installer, it instantly crashes. I want to know how to change the installation file path from system to applications as every time I try the installer again, even after deleting the old one and downloading a new one, it does not prompt me to "where to instal"