How do you thread a Merrow M-3DW-2?

To thread a Merrow M-3DW-2, first, raise the presser foot and turn the handwheel to position the needle at its highest point. Then, follow the threading guide on the machine, starting with the upper thread and ensuring it goes through the tension discs, guides, and needle. Next, thread the lower looper and upper looper, making sure to properly route the threads through their respective paths. Finally, pull the threads to ensure they are secure and make a test stitch to verify proper threading.