It's easier than you would think.

using Windows:
Go to your windows explorer
put your floppy disk into the drive
select the drive (usually drive a:)
right click on the drive
select "format disk"
Now a format menu will appear. You can select Quickformat here (please do) BUT ALSO 'format MS DOS compatible disk' Do this.

After the formatting is done, copy the WDIDLE program to the disk.

Reboot your PC with the floppy disk inserted. Make sure to select the floppy disk as the first boot device in your PC's BIOS.

You will now boot into DOS mode.

Type WDIDLE3 /S30

Done.

In case your PC does not have a floppy drive anymore, get your hands on a USB floppy drive. The procedure is exactly the same. The only difference is you will need to select "usb floppy drive" as your primary boot device instead of "floppy drive" then.