Very good. There are a few ways to install runners but it depends on the type of carpeting. It could be tacked or stapled or even glued depending on the type of carpet. First, pick out the type of carpet you and the Landlord want. Then, go to the WEB site I gave earlier for more info (or e-mail them with what you have to 'work with'), or talk to the Retailer you buy the carpet from about installation procedures. If it's just a runner, it should be REAL easy (based on instinct although I've never done it.)
Other than that, wait a few days to see if anyone else has more to offer. In the meantime, if you know the type of carpet, post back with the width of it as well as the width of the stairs. (By definition, a runner is NOT stringer-to-stringer.) For now, my best to ya and hope this helps.