Do not rotate the camshaft(s) or crankshaft when the timing belt is removed or damage to the engine may occur. Begin by removing the timing belt. Rotate the crankshaft counterclockwise until the crankshaft sprocket is three teeth BTDC to prevent engine damage if the camshaft sprocket is inadvertently rotated during sprocket bolt removal. While holding the camshaft sprocket, remove the camshaft sprocket bolt, then use two large screwdrivers to lever the sprocket off the camshaft. To hold the camshaft/sprocket while loosening the bolt, a strap-type damper/pulley holder tool is recommended and is available at most auto parts stores; if unavailable, remove the valve cover to access the wrenching flats on the camshaft for 2.4L engines only. For 2.0L engines, remove the two bolts securing the tensioner pulley bracket to the engine block and remove the pulley and bracket assembly without attempting to loosen the center bolt on the pulley or the pulley pivot bolt. For 2.4L engines, remove the idler pulley. For 2.0L engines equipped with a hydraulic timing belt tensioner, remove the tensioner pulley. Remove the bolts securing the rear cover to the engine block and cylinder head, then take off the rear cover. Carefully pry out the camshaft oil seal using a small screwdriver, ensuring not to nick or scratch the camshaft or seal bore. Clean the bore and coat the outer edge of the new seal with engine oil or multi-purpose grease, also lubricating the seal lip. Using a socket with an outside diameter slightly smaller than the outside diameter of the seal and a hammer, carefully drive the new seal into the cylinder head until it's flush with the face of the cylinder head; if a socket isn't available, a short section of pipe can be used. If engine location makes it difficult to use a hammer, fabricate a seal installation tool from a piece of pipe cut to the appropriate length, a bolt, and a large washer to press the seal into the bore by tightening the bolt. Install the rear timing belt cover, tensioner pulley/bracket, idler pulley, and tensioner pulley as applicable. Install the camshaft sprocket, aligning the pin in the camshaft with the hole in the sprocket, and use an appropriate tool to hold the camshaft sprocket while tightening the sprocket bolt to the specified torque. Reinstall the timing belt and run the engine to check for oil leaks.