Get a cardio monitor, I like the ones that strap around the chest and send to a wrist display. Do cardio of your choice,...I prefer a ten speed bicycle mounted on a "wind trainer", mine is a squirrel cage fan connected to the back wheel,...put it in front of a TV, with DVDs of your choice,...raise your heart rate to a mere 130 beats a minute for only five minutes the first day, use a timer so you don't be a clock watcher.
Wait a day, then do it again for 6 minutes, wait a day and so forth, adding one minute each time. After several weeks you are going thirty to forty minutes non stop,...now you start raising your heart rate a little each time until its around 150-170 beats a minute,...when you are doing 30-40 minutes at 150-170 a minutes every other day,...those stairs won't mean much...
It's important to have the TV with programming you enjoy,...no tedium then.