Moving it up 1 flight of stairs.
Ask them, you need help for moving the printer 1 flight of stairs. You must be 2 for moving it, but a friend could do the job.
Setting it up physically?
Documentation is good (at least with Windows).
Setting it up physically takes time but is easy with the documentation.
Setting it up to the PC?
Setting it up to the PC suppose you are used to pro printers. If you have no or only little practice and knowledge, pay for the setting up. They will do the connection, the driver update, calibrate at least one paper, and make one profile. Keep them until you have a good print from Photoshop or your print soft.
The easiest way to learn to use the HP driver. It should worth the money, if they are qualified of course...