To accomplish this task, start by raising the front of the car and putting it on jack stands, then taking off the front wheel. If it is required to dismantle the suspension unit in the engine compartment, remove the dust cap and loosen the piston rod nut, without removing it, to avoid injury. Remove the spring clip which retains the brake hose and separate the brake hose from the bracket and on ABS models remove the bolt which retains the sensor to the steering knuckle and any bolts which secure the wiring to suspension and position the ABS sensor out of the way. Detach the bolts and nuts securing the suspension unit to the steering knuckle to free the knuckle from the suspension unit. Note the location of the outer suspension unit upper mounting in relation to the inner mudguard panel and remove the retaining nuts. Carefully lift the suspension unit from the vehicle to avoid damaging the drive shaft boot. Clamp the bottom-side of the suspension unit assembly in a vice. Install a spring compressor and compress the spring coil. Remove the piston rod nut and discard. Make a mark on the coil spring position concerning the upper spring seat, lower spring seat and insulator. Now, detach the upper mounting, washer, upper spring seat, insulator, spring, dust cover and lower insulator from the suspension unit. Test the shock absorber by moving the piston rod up and down. It should give firm pressure and no slack spots. Check for the presence of any fluid leaks. If there is excessive leakage or no pressure, the shock needs renewal. Also, always renew a pair. Scrutinize the top mounting assembly for any damage and fatigue; check on the bearing for wear and tear; check all rubber components for grade and renew any worn or damaged parts. Examine the coil spring for fatigue by comparing it with that of the same model new car. Check the coil springs for cracks and damage, if defective, it is advisable to renew the springs on both sides. For the assembly and installation, follow the reverse order of the disassembly and removal; ensure that the insulator is properly located onto the lower spring seat, install the dust cover and compress the coil spring. Ensure that the markings made during disassembly are in alignment. Finally, install the upper insulator, spring seat, washer and mounting, ensuring proper alignment. Attach a new piston rod nut to the suspension unit and tighten it while holding the upper mounting to prevent it from turning. A coil spring compressor enables slow release. As it's released, check that the end of the top coil sits against the end of the upper spring seat and that the end of the lower coil seats against the end of the lower spring seat. Finally tighten the piston rod nut to the correct torque. In case the suspension unit cannot be held, fit it to the vehicle first before torqueing the piston rod nut to specs. Using multi-purpose grease, pack the recess at the top of the upper mounting bearing and fit the dust cap, ensuring no grease gets on the rubber. Attach the suspension unit to the upper mounting by installing it loosely with the retaining nuts. Connect the suspension unit to the steering knuckle and tighten the retaining nuts (bolts) to the required torque. Lastly, fit the front wheel, lower the vehicle to the ground, and tighten the upper mounting retaining nuts to specifications, ensuring that the piston rod nut is tightened to specifications and the dust cap is fitted if it has not been done, followed by checking and if necessary adjusting the front wheel alignment.