Connect everything accordingly to a connection diagram:
(If your TV doesn't have an HDMI interface, then connect it to recorders "s-video out" or "component video out")
Put the source VHS into the VCR drive and the DVD media into the DVD Recorder drive.
Press "DVD" on the remote and select the "AV IN1" input line. You can do it with "AV INPUT" button on the remote.
Staying in DVD mode press REC to start DVD recording. Immediately after that go to VHS mode ("VHS" button on remote) and press PLAY. The VHS playback and DVD recording are now in progress...
Grex light indicator in this period should be steady or fast blinking red.
When you will need to stop recording press STOP in VHS mode. This will stop VHS playback.
Switch to DVD mode and press STOP. This will stop DVD recording. You will see the message "Updating the information of disk..." for a few time.
Now you can play the recorded video. You may need to finalize new DVD if you are going to watch it on another DVD player.