It is possible to replace switches that have a LED in the switch, but you need to desolder the LED before either opening or desoldering the switch.
The k65 RGB will not allow you to open the switches without desoldering, as the switches are plate mounted and there is not enough space for the switches to unlatch without removing them from the plate. The RBG LEDs in this board are also mounted differently than normal LEDs in cherry switches -- rather than having the LED mounted through the switch, the RGB LEDs are soldered on the PCB below the switch, and as far as I know, are not attached to the switch at all.
As I said in your other thread, I'm not sure you will be happy with the results of making ergo clears with springs from MX reds, as occasionally the spring fails to return the clear slider to the original position, leading to a key being stuck down.
Note that the design of the RGB switch housing is different from a regular MX compatible housing, to diffuse the surface mount LED through the housing. If you replace the RGB switches with standard MX switches, even if they appear to have clear housings like the zealios, you may run into issues with the lighting.
If you want to keep the RGB, and have an ergo clear-like feeling, I would surmise that your best bet is to buy purple zealios (or MX clears and 62g springs), and switch the internals (spring and stem) into the RGB housing.