CRG 2000-up rear calipers are the same as VEN05 front brake calipers. So they do share the same pad design. But be aware that the VEN05 rear calipers (and thus pads) are very different from the 2000-up.
I have two CRG karts with 2000-up rear braking systems and I prefer the Ferodo Kart Attack pads – for feel, longevity and price. FWIW.
Replacement is really simple. Remove the pad retaining clip and bolt, and pull the old pads out. Press the pistons all the way back inside the caliper, and insert the new pads. I find removing the master cylinder cover(s) helps the pistons to retract easier. As long as nothing leaks and the system is working well you’ll be fine. I’d inspect the brake fluid at the time and flush the system if its dirty, or top it off if its low (after replacing the pads so that the pistons are reset).
Remember t0 replace the master cylinder covers before you pressurize the system with the pedal. If you leave the covers off, the fluid will shoot out of the top.