The following two videos show in detail how to proceed in changing the timing belt and water pump in a Peugeot 206 with 1.4 L engine. The timing belt has to be changed every 90,000 km or 5 years, whichever comes first. In most cases, it's a good idea to change the water pump during this work, too. Exceptions may be low mileage or a recently changed pump.
NOTE: These videos are in German, but contain English subtitles.
The first video shows you how to change the timing belt only:
The second video demonstrates the additional steps needed in order to change the water pump:
Peugeot uses a cooling liquid which is not common in all countries. Therefore the liquid has been changed to the liquid Volkswagen uses. This is no problem for the engine, but you have to drain the liquid completely, refill it with pure water and drain again before you fill the system with the new cooling liquid.
For this repair, some special tools are needed. In order to remove the drive belt, you need a 10mm male square. For tensioning the timing belt, you will need a 8mm male square. For adjusting the timining of the engine, the Camshaft is fixed by a 10mm bolt, the crankshaft is blocked by a 6mm bolt. You may buy these tools, but I made them myself.
Enjoy your repair!