agreed. pics not much help. You probably don’t really want to bring a lift into the house. If that was the thing to do then youd want to ask the rental company what they recommend. scaffolding is prob your best option. but…
what about a little giant stle ladder. I just picked up a 24’ folding ladder from home depot for $250ish. Usually you can set them up on stairs when you have them in the step ladder position. Just lower one side of the legs a little more for the lower steps if that makes sense. Sometimes it doesn’t work on round staircases though.