2. Using a 10 mm socket wrench placed on the nut securing the rear timing belt cover, hold the camshaft pulley from turning, and use a 17 mm wrench to loosen the pulley mounting bolt.
3. Remove the pulley from the cotton wool.
4. Remove the key from the groove.
Warning: When performing the following operation, be careful not to scratch the working surface of the shaft.
5. Pry and remove the seal from the mounting hole using a hook, screwdriver or pliers with curved jaws.
6. Lubricate the working surface of the new seal with clean engine oil and carefully place the seal on the shaft.
(Article copied from a web page: ladaman.ru)
7. Press in the new seal using a special mandrel or a 30 mm socket head.
8. Install the timing belt ("Timing Belt - Replacement").
9. Install the parts removed during disassembly.