This can be a major job if you are not sure what you are doing, but basically anyone can do it. first of all you need drain the oil from the sump plug on the bottom of the gearbox and disconnect the battery..Then remove the starter motor( 2Bolts), You shouldn't have to undo the battery cables from the back of it as you will just need to pull it out of the way. then remove the driveshaft (the shaft that travels from the rear of the gearbox to the differential, (The centre of the back wheels)(4 bolts). When you have undone the 4 bolts from the driveshaft, slide it out from the gearbox. Find the clutch slave cylinder and unbolt it from the side of the gearbox and also the speedo cable and reversing light wires. Once that is completed you will need to remove all of the bolts from the front end of the gearbox that secures it to the motor. Then from inside the ute you will need to remove the rubber glove on the gearstick and unbolt the gearlever and remove it. Now hop back under and undo the large bolts that hold the crossmember(a steel frame that goes under the tail of the gearbox and fro mone side of the vehicle to the other) The gearbox will then pull out from the engine (Flywheel) BE AWARE: This is a heavy unit, where possible use jacks. Once the gearbox has been removed you will see on the back of the engine a wheel with teeth.(Flywheel) The unit that is bolted to it is known as the pressure plate and tucked in behind it is the clutchplate. Unbolt the pressure plate and both units will fall away. These are the parts you will need to replace.
CAUTION: Check which way the clutch plate is facing when it comes out as it can only be replaced the same way. When you replace clutch plate and the pressure plate you would be best to see if you can hire a spigot shaft from your local garage(This is a shaft that you use to line up the clutch plateso that the gearbox will slide back in)while lining up the clutch plate you will need to leave the bolts on the pressure plate loose and only tighten when everything lines up right. Then it is just a case of reassembling everything in the opposite order from the way you dismantled it. Bleed the clutch and your done.
The whole job will take about 4-6 hours if you have everything you need. Good luck.
Mechanic
Petrol mechanic. 25 years experience