Here is a link to a YouTube video showing an emergency road-side belt change:
https://www.youtube.com/watch?v=G40VUru4xJI
Kind of a long video for a 40 minute job under garage conditions.
However it does show that the job can be done under worse-case conditions. Given the right tools at hand you wont be stranded.
And thanks to The Bern here is a link to an emergency road-side variator removal done without using a special variator holder tool:
https://m.youtube.com/watch?v=-G_4xK1QCeM
Here is a link to the forum post showing the Home Shop method for changing the belt:
https://www.silverwing600.com/t8013-belt-change-video-home-shop-method