You let it go until the yeast decide they are done. Once you introduce yeast to the wort, they are in charge and do their thing at whatever pace they decide. I can tell you though that one week is not enough. I've done several of their kits and to start with I followed their directions. Their directions are wrong, designed to get you to purchase more kits soon. Once I started reading here on HomeBrewTalk, I realized how badly wrong the kit instructions were and started leaving my brew in the fermenter longer and I soon realized how much better they turned out.
Then I read further and found that I had been fermenting too warm and started fermenting where it was cooler and found that I often had airlock activity on the 5th day. Now airlock activity doesn't necessarily mean fermentation is still going on but from other signs I could tell that it was. What a difference in beers when you ferment them cooler and longer.
Yeast only produce CO2 for the first part of the ferment as they are processing a lot of sugars. Once the sugar is gone, the production of CO2 and most of the alcohol is over but the yeast still have work to do as they clean up the mess they made during the fast part of the ferment. You can't see what they are doing, but take my word for it, they are working.
Give your yeast at least 2 weeks before you do anything. If you are in a hurry, take a hydrometer sample at 2 weeks, then again 3 days later. If the reading hasn't changed, you can bottle or you can be patient and let it have another week or even 2 before you bottle.
