Importing Altium to KiCad

I am currently importing Altium projects into KiCad. I’m using the 7.0.11. It imports the schematics and PCB into a local library just fine.
I then need to change the parts from the local library to a database that we have.
The database serves Altium & KiCad. All the part names, symbol names & footprint names are the same in Altium & KiCad, but where the symbols & footprints come from are different (of course).
I then manually change each KiCad symbols from the local library to the database and all is well. But this takes some time as I have multiple sheets per design.
Playing around, I wrote a Python script that goes into the .kicad_pcb file and updates all the footprints to the database, which works. But updating the schematic from PCB doesn’t seem to change the schematic.
I’ve been trying to manually edit the .kicad_sch file in my text editor to see if I can change just 1 schematic part to the database without success.
Any thoughts would be appreciated.