How to play on the Schedule 1 beta branch for early access to new updates

Sometimes I can't bear the wait, and I'm ready to try out any new gadgets or gizmos as early as possible through the Schedule 1 beta branch. Fortunately for me (and the rest of you drug kingpin hopefuls), TVGS seems keen to share new Schedule 1 updates days before they go live for everyone through test builds.

Test builds don't always make for the most stable Schedule 1 experience, but I've always had a good time trying out early builds to see what I can expect in the next big update. As long as you back up your save file...