I ran python3 -m pip install -U discord.py but it only installed discord.py v0.16.x. How do I install the new discord.py rewrite v1.0? 
I uninstalled the old discord.py using pip uninstall discord.py and re-ran pip to install discord.py, only to get version v0.16.x again instead of the new v1.0 version.
Open CMD and go to the folder of your discord bot eg:
cd C:\Users\max\Desktop\DiscordBot
Next type this in CMD: pip install discord.py
That should work
How to install discord.py rewrite?