It’s a matter of adding pickup rollers and possibly 3 rail wheelsets. I can’t comment as I’ve never done one but it seems pretty straight forward.
Many 3 railers who run Kadee’s , want fixed pilots and proper handrails opt for these models. Adding the rollers and wheels is easier than tackling the fixed pilots in some cases.
The question is are you looking to go for 3 rail scale and keep the Kadee’s or do a full blown conversion with coil couplers and swinging pilots.