Do not rotate the camshafts or crankshaft when the timing belt is removed or damage to the engine may occur. Start by taking out the timing belt. Turn the crankshaft counterclockwise until the crankshaft sprocket is three notches BTDC to keep the engine from being damaged in case the camshaft sprocket is accidentally turned in the removal process. Keep the camshaft still, and then remove the bolt that attaches the camshaft sprocket, then apply two large screwdrivers to push the sprocket off the camshaft. This procedure is recommended to be performed with a strap-type damper/pulley holder tool; however, when the old timing belt is not reused, a section of one can be wrapped around the sprocket and can be held in place using a chain wrench. Cautiously loosen the camshaft oil seal with a small hooked tool or screwdriver, being careful not to nick or scratch the camshaft or seal bore, because any damage will result in leakage by a new seal. Wipe the bore, and apply engine oil or multi-purpose grease to the outer edge of the new seal, lubricating the seal lip. With a socket whose outside diameter is slightly less than the seal and a hammer, very cautiously drive the new seal into the cylinder head until it is level with the face of the cylinder head. If a socket isn't available, a short section of pipe can be used. When space is too small to use a hammer, make a fabricated seal installation tool by cutting a piece of pipe, a bolt and a large washer to stamp the seal into the bore. Install the camshaft sprocker, fitting the pin in the camshaft into the hole in the sprocker, and tighten camshaft sprocker bolt to the desired torque. Lastly, fit the timing belt and start the engine to test against oil leaks.