The schedule is complicated, and in case of errors, serious damage can be done to the engine; hence, only highly experienced people can perform this process, and it is recommended to seek the advice of the expert in case of any doubts. The first step is to unplug the negative battery cable and block the rear wheels when placing the parking brake. In SOHC models, disconnect the under cover splash shield, power steering and air conditioner drivebelt, where fitted, and alternator drivebelt, spark plugs, water pump pulley bolts, crankshaft pulley bolts, crankshaft pulley. Unscrew the crankshaft sprocker center bolt, timing belt guide and timing belt covers and position the crankshaft and camshaft sprocker marks aligned and loosen the timing belt tensioner before removing and uncoring the timing belt. Should there be need to do so, withdraw the camshaft sprocket(s) to insert the seal(s) and avoid the rotation of the camshaft. In the case of DOHC engine, take off engine under cover shield, power steering and /or air conditioning drivebelt, alternator drivebelt, water pump pulley bolts, spark plugs, oil dipstick, crankshaft pulley plate bolts. You will need to remove timing belt covers, center bolt on the crankshaft sprocker, and the timing belt guide then line up the crankshaft and camshaft sprocker marks and loosen the timing belt tensioner then take off the timing belt. Check the idler pulleys and examine their smooth movement, any excessive movement and debris that may have contaminated the timing belt. When the timing belt exhibits wear or any other damages, it should be replaced with a new one, though such problems, which led to the old belt failure, should be repaired. When installing, wipe down the timing belt area, and place the idler pulleys and tensioner in place and that the sprocket marks are aligned correctly. Install the timing belt over the sprockers, place tension and ensure alignment after turning the crankshaft. Lastly, after removing all the parts, place them back in their correct sequence and make sure that the engine is functioning rightly and that the timing belt has been properly installed so as to prevent any severe engine damage.