Just copy the template files you made
to a usb stick and copy them to the other computers in correct locations.
Once you completed the custom things that you wish to do, the video shows you how to save it as a part template so that future part files will retain these custom things you did. You can navigate to the folder where this part template is saved to, copy it to your USB stick, paste that file into referenced folders for part templates on other computers, and that should be all that's needed for each computer.
You just need to copy the updated part and assembly template files from your computer to the other computers.
If you have a network in your office, this is a prime example of why it is a best practice to have templates and other common files on a shared network location accessed by all SW users. No need to have multiple redundant duplicate files.
Short of that, if you are not sure where these template files are located on your machine, look at Options / System Options / File Locations / Document Templates for the path to the containing folder. Open that location in Windows Explorer and copy the part.prtdot and the assem.asmdot files to your usb stick. Paste these same files onto the other machines in the file location they have mapped for their template files.
As a consideration, instead of overwriting the original template files, you might name your updated template files to something like Part [Z-Up].prtdot and Assembly [Z-Up].asmdot. This will allow the user the choice of basing a part / assembly on either triad orientation depending on the template selected.