As other have said. Try to get the door off. Not only will it significantly lighten the load but it will also give you a a spot to grab. Also do your measurements first and carefully. You don't want to get near the bottom of the stairs only to find out you need to remove the door or in my case the entire door frame. I was able to do mine solo with a motorcycle lift and some 2x4s and 2x6s but I also didn't have a set of stairs just a plate to get over.