Find a server with Dyno bot in it
Find the bots channel (if it has one)
Do ?discrim
Pick one from the list (it doesnt matter which)
Copy the username (without the #????)
Change your username to the one you copied
Since there cannot be two users with the same discriminator and username, it changes your discriminator
You can now change your username back to the original
YOU NOW HAVE A DIFFERENT DISCRIMINATOR
Proof it worked