it's pretty straightforward now, used to be a pain to get long videos on youtube but not now.
Assuming you've already copied the old video tape onto a DVD, first step is to pop the DVD into your computer and get it converted to an MP4.
The very user friendly and free means I found for this is to download software called HandBrake (its safe).
https://handbrake.fr/
Once you have downloaded this software, open it up while the DVD of the game is inserted in your computer.
http://www.techsupportalert.com/content/rip-dvd-movie.htm
When you have the HandBrake application opened, go to the top of the screen where it says "source" and enter your DVD drive location on your computer. Then in the middle where it says "Destination" select where you want to save this video to, i.e. the "my documents" part of your computer or whereever. The output setting should default to saving it as an MP4 which is what you want. Just make sure it says MP4 on the screen. Then hit the green "Start" button at top.
When its finished you'll have a playable MP4 video of the game saved on your computer. Then go to your youtube account and log in, and there will be an "upload" button up at the top of your youtube account page screen. From there, all you have to do is select the MP4 file as what you want to upload and hit start and "publish" and youtube does all the rest. with the longer full game videos it does take quite awhile to upload but that's all there is to it.
Oh and one last thing, if you haven't used or uploaded with your youtube account in awhile, like me, youtube may ask you to enter in a phone number to "verify your account" to get permission to upload longer videos. If you give them your phone number it then texts you a password to verify your account and when you enter that password into the youtube page, it then grants you the ability to upload the longer multi-hour videos.
Edited by McMuffin at 12:52:43 on 10/13/16