You can delete the main file and then create a new java file using shell commands: (hit ctrl+shift+s)

rm main.java

but then you will also have to configure the run button: (create a .replit file)

run="sh main.sh"

# main.sh
javac NewClass.java # whatever that file is
java NewClass

But

You can create a new file and rename it with your choice...
Unfortunately, you cannot rename the original (main.java) to somewhat other.

If

you wanted to run your second file, then write this code into your main file:-

otherfile.main(args);

If

You wanted to rename your file on Desktop then, You can download it as a zip and extract it, and then you can rename it.

That's probably unrelated here :D

Hope this helps

Please mark my answer if this helps

In the console, type rm Main.java, then hit the "new file" button, and rename the file whatever you like. Then create a new file called .replit, and type this:

run="javac filename.java; java filename"

I don't do java, so that may be wrong

Sort of.