The front two were easy, but because of the unit and table either side, the only way I could get to the rear ones was to lean over the side of the chair and pull myself up, thus pulling the chair forward onto its front wheels so I could put the rear casters back under.
Complicated? It was!
Anyway, as I'm sure that you can picture the scenario in your heads... yes, I overbalanced.
I fell down on the floor, via the table... so I now have this fantastically amazing scratch down my side. And yes, it bloody hurt, thanks for asking. I'll probably post a picture of how it looks now, tomorrow... along with another one which may show a nice purple and blue bruise! *wince*