If you are stuck at step 1 because you do not see the Tools -> Install “processing-java” menu item, this video is what did it for me:
Essentially, I had to manually add processing to the PATH environment variable (the part from 3:27 to 4:56 in the video above)
In a nutshell
- Look up where processing is installed and copy the path
- Open the system settings and search for “advanced system settings”
- Click on “Environment Variables…”
- In “user variables for {yourName}” double click the line that says “Path”
- Click on “New” and paste the path where Processing is located. It should look something like the screenshot below
- Follow the rest of the steps in @michaelPaulukonis’ post above and you should have a working setup