are you asking if you can convert a PCB mount keyboard to plate mount? if it's a standard form factor like TKL/104 there are some plates people sell but you'll have to desolder the switches before you put them on
the other way around I need the switches for a gon build
No problem. PCB cherry can be easily converted to Plated one by cutting the 2 plastic leg with a good snip/wirecutter/etc and craft knife. I believe GON pcb has holes for PCB switches right? You might not even need to cut them unless there is some fitting issue.
OP wants Plate to PCB.
The only part that changes is the lower switch housing unit. PCB mount has two extra plastic legs. If you have diodes/LED's, those will also work to secure the switch in place. An old board I have even uses metal "staples' soldered to the pcb for stability.
If your GON doesn't have a plate, your best bet would be to buy PCB mount housing units (or buy PCB mount switches, swap the internals, and sell your plate mount ones).