I hereby certify that I am not simply asking someone else to design a footprint for me.
In Kicad PCB I have been selecting and editing one footprint at a time. Can I select multiple instances of the same footprint for editing? Like say I want to change the pad hole sizes from 30 to 35 mils? Thanks!
If its the same footprint then it sounds like you are making a custom version of an existing footprint ? why not edit the footprint in the footprint editor and save it as a custom version to a personal library, then you can apply that footprint to the relevant symbol properties in the schematic and update the PCB. (or you can update the footprint on the PCB)
The question is (for me) not 100% clear (and jmk & raptor also have interpreted it differently).
Do you want to change properties of multiple pads in the footprint editor? → see jmk
Do you want to change the footprint-properties for multiple footprints on board-level (in the pcb-editor)? Than I second raptor suggestion → create a custom footprint with the modifed pads.
sidenote: always add the used kicad-version to your questions. The answer to a question could depend on the used version. (currently the forum gets questions to 4 versions - from v5 - v6 - v7 (current stable version) and sometimes already v7.99 (==the future v8).