Assuming you are using a standard 2 scout then 2 rocketeers setup. Use your expandable scouts to force the cyberdiscs to waste their reaction shot. Use you other one to smoke the ramp (switched to instant grenade
). Have your 2 rocketeers step down and fire at the cyberdiscs / stay in the craft and fire at those right in front.
Once your soldiers have stepped down make sure you got your second scout staying in the skyranger. His job will be throwing ammunitions to the two rocketeers.
Works, is fun and also more rewarding than the grenade relay tactic.
Edit: Also don't forget to unload any rocket launcher that isn't going to be used on this turn. As mentinned by yrizoud Cyberdisc are almost if not always with sectoids using psionic attacks. I usually keep the rocket in the other hand for fast reload. Because if your rocketeers are psi-attacked they might go berserk or get taken over by aliens. In both cases the skyranger turns into a frying pan.