You will need: all the tools needed to remove the timing drive (see "Replacing the timing belt and tension roller"), as well as a 17 mm wrench, a device for fixing the camshafts from turning, a flat-blade screwdriver, and a hammer.
1. Disconnect the wire from the negative terminal of the battery.
2. Set the piston of the 1st cylinder to the TDC position of the compression stroke (see "Setting the piston of the first cylinder to the TDC position of the compression stroke").
3. Remove the timing belt (see "Replacing the timing belt and tension roller").
4. Remove the camshaft pulleys (see "Replacing the cylinder head gasket").
5. Remove the keys from the camshaft grooves.
6. Using a screwdriver, remove the seals.
7. Before installing new seals, inspect the working edges 1. They should be smooth, without tears, dents or rubber build-up. The springs of the 2 oil seals must be intact and not stretched. Lubricate the working edges with engine oil.
Note: To make it easier to press in the seals, make small chamfers on their seating edges using a file or emery wheel.
8. Lubricate the working lips of the oil seals with engine oil.
9. Install the oil seals with the working edges inside the cylinder head, carefully tuck the working edges onto the camshafts using a wooden stick...
10. ...and press it in until it stops using a suitable mandrel. A suitable sized head from the tool kit can be used as a mandrel.
11. Install all parts in the reverse order of removal. In this case, install the inlet camshaft pulley with the disk that ensures the operation of the phase sensor facing the engine. Install the exhaust camshaft pulley in the same manner. Adjust the timing belt tension (see "Replacing the timing belt and tension roller") and the generator drive belt (see "Replacing the alternator drive belt").