I think you might need to take this opportunity to learn how to leverage the API. This looks spot on for what you want to do: https://developer.cisco.com/meraki/build/mx-firewall-control-python-script/
As for quick, it may be a wash comparing how long to copy paste them manually vs. getting a script setup, tested and working, but once you have this setup you should be able to make large batch changes quickly next time.
Best.
- Ex community all-star (⌐⊙_⊙)