I couldn't find a guide on how to take apart a K65, so this is mine.
So disassembly is pretty easy. If you know there's a hidden screw under the Corsair emblem thing (that took me like 30 minutes to figure out z.z)

Now the metal part should just lift right up, but the next PITA will be this thing

It's held in with just some simple little tabs you have to loosen. You don't have to remove the USB or ribbon cable just yet.

Then you can remove the plastic pieces if you need to do stuff like swap switches. Leaving you with just the plate/pcb/switches

The "new" switches harvested from a broken Rk-9k I got for $25


Also each corner switch has one of the switch leads bent to hold the PCB

Take off the PCB after much desoldering.

Pop all the red switches out

And re-assemble, I forgot to take a pic of the naked board with just MX browns and I was half way through putting the caps back on.

One thing I didn't do was put the screw back in under the corsair logo. I think it will be good enough with the other 19 screws holding it together, and makes it easier in the future to take it apart if need be.
Kthx for looking at the pretty pictures.