good advice above.

on all my derailleur, the bracket that holds the chain has a screw on it. I unscrew that screw, take the chain out, and manually put the chain in either of the bigger two gears.

The limiter screw isn't a bad idea, but
1) you limiter has to have a pretty large range to block out the smaller gear
2) you have to re-adjust the limiter to get it back to where you are now.
(neither of those is a deal breaker, just something to consider).