How can I install pure android and get rid of bloatware?
There's no official way to install a "pure Android" ROM: the only official ROM is that provided by the manufacturer.

As sameer says in the comments, you can disable bloatware apps from the settings, with almost the same effect as uninstalling them.

If you want to start from a clean slate, you should look for an AOSP-based custom (unofficial) ROM. Although they aren't always as reliable as the manufacturer's ROM, because they're made by third-party volunteers, for the more popular devices with better manufacturer support they can be very reliable and even better tuned than the original ROM. Start your search at Where can I find stock or custom ROMs for my Android device?