The normal link between schematic symbols in Eeschema and existing Footprints in Pcbnew for a project is done with “timestamps” a.k.a. “UUID”.
Therefore the “Match Method” should be “Keep existing symbol to footprint associations”
With “Options” also check “Update footprints”.
The “Update footprints” is not relevant here. With a test it also updates the Refdes of a footprint if this checkbox is unchecked.
In the text box with “Changes to be Applied” there is a listing of text of what Eeschema will do when you execute the command.
In the screenshot below, I changed the RefDes: “Q345” to “Q42”, and KiCad tells me it’s doing something good with green text.
If you still can’t get it to work, then make a new small project (or a copy of your existing project) and experiment a bit with just a handful of components.
If you then still can’t figure it out, post some screenshots, and/or the full text here.
Below a part of the copied text (normal [Ctrl +C] and [Ctrl = V] in this forum):
Info: Processing component “R36:/5F575744:Resistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal”.
Change Q345 reference to Q42.
Add net Net-(Q42-Pad1).
Reconnect Q345 pin 1 from Net-(Q345-Pad1) to Net-(Q42-Pad1).
Add net Net-(Q42-Pad3).
Reconnect Q345 pin 3 from Net-(Q345-Pad3) to Net-(Q42-Pad3).
Add net Net-(Q42-Pad2).
Reconnect Q345 pin 2 from Net-(Q345-Pad2) to Net-(Q42-Pad2).