If you're talking about the pressure plate and clutch plate, you need to remove the transfer case and transmission. If you have a substantial enough transmission jack, you can remove the t-case, transmission, and bell housing all as one unit. If not, you'll need to remove each component individually. Once you've got the bell housing off, you replace the clutch plate and pressure plate. While you're at it, you should replace the pilot bearing and throwout bearing, as well, and inspect your clutch fork for damage, and replace if needed.
Once you put the clutch plate and pressure plate back on, it's absolutely imperative that you torque them to specification. Once all that's done, you put the bell housing, transmission, and t-case back on, then reconnect your driveshafts.