Mojang Server Blacklist allows you to bypass the server blacklist in order to join certain EULA-infringing servers.
To do this, we use Java Agents in order to retransform Mojang's custom Netty bootstrapper.
In order to use this you will want to head on over to the releases section of this repository, and download the latest release.
Then, inside your Minecraft launcher, edit your profile and edit the JVM arguments: prepending this:
-javaagent:/path/to/MojangServerBlacklist.jar
Make sure you change the path to wherever you are storing the jar! I recommend keeping it in your .minecraft folder.
If your path has spaces in it, you will need to wrap it in double-quotes, like so:
-javaagent:"/path with spaces/to/MojangServerBlacklist.jar"