Copy that internal ZIP to the root directory of a microSD card.

Since the official system is now very old, many users install custom ROMs to access newer apps. :

Are you looking to your tablet to its original state, or are you trying to upgrade it to a newer version of Android? ASUS Transformer Pad (TF300TG) - Support

: The most active repository for these files and step-by-step guides is the TF300T/TG development forum on XDA . Critical Safety Tips