Before doing anything, all alternatives must be exhausted if the coil spring or strut reveals signs of wear like dripping fluid, decreased damping force or chipped, sagging and fractured coil springs. Replacement is the only option for the strut/
Shock Absorber assemblies once they have a problem. Nonetheless, there might be available strut assemblies complete with springs on an exchange basis which can save your time and effort. Before disassembling the vehicle it's advisable to do a part cost and availability check. Remove the upper spring seat and insulator from the damper shaft. Take off the upper shock mounting nut with a socket wrench and remove all fasteners that secure the assembly to its mountings. Loosen the damper shaft nut and remove the nut as well as suspension support. Examine suspension support bearing for smooth operation and replace if necessary. Inspect rubber portion of suspension support for cracking or deterioration; if separate replace it. Loosen connector nut for shock absorber rod eye end by a spanner wrench then pull out shock absorber rod without disconnecting upper suspension arm from knuckle arm (2001-2005 ES300). Put spring compressor on spring so as to unload pressure from upper spring seat. Remove dust seal and suspension support off of damper shaft after carefully observing this procedure otherwise you will not be able to install it properly during reassembly stage. Gently lift compressed spring away from assembly keeping it aside afterwards. Slide rubber bumper off damper shaft thereby examining lower insulator for wear, cracking or hardness replacing if necessary in case any defect is found. If new lower insulator is being installed, set it into position with dropped portion seated in lowest seat inside opening. Extend damper rod then fit rubber bumper into place. Place coil spring over lower insulator ensuring end of spring fits into recessed part of lower seat. Install upper insulator and spring seat aligning flats on damper shaft with those in spring seat. Align the OUT mark on the upper spring seat with mark on upper insulator. When working on a front strut, make sure arrow on spring seat points towards lower bracket. When servicing the rear strut, put suspension support so that pointed end faces out and hole is centered on strut bracket. Install dust seal and suspension support to damper shaft; then tighten nut to specifications mentioned in manual. Remove spring compressor tool from between lower control arm and coil spring. Finally, fixate the strut spring assembly into its place.