How to change video line without a remote

Question

we're trying to connect a new Sony dvd/vcr unit to an old zenith television. spoke with sony and cabling seems to be done correctly. neither a vcr tape or dvd was playable. also tried setting the clock to no avail. they asked me to make certain television was set for video 1 or 2. but without the old remote for this tv, we don't seem to be able to do this through the "menu" button.any suggestions?