Well, I don't have 231 pleos laying around . . . . Actually, if you left the pleos in the boxes, you could probably build a Jenga-like tower with as few as 21 pleos.
The two pleos walking in circles are the two pressing their bodies against the light bulb, so they are obviously at the top. That's why the pleo pile has to be so big -- you need room on the top of the pile for them to walk around! You need the two pressing their sides against the light bulb, because I couldn't think of any other way to grab the bulb. Pleos don't have hands and the fat part of the bulb (which is what they would have to grab) won't fit in their mouth. The two bodies on either side, with the rubbery skin, would provide the grip to hold the bulb and unscrew it.
I figured for the pile on a modified version of the human pyramid. 12 pleos on the bottom layer with a board across their backs to support the next layer . . . eight layers up, and you'd need three groups like this head-to-tail so that you'd have a 5x3 pleo platform on the top for the two pleos doing the screwing/unscrewing to walk on. This leaves 21 pleos to act as the ramp to provide a less-steep slope for the pleo with the new bulb to climb up and down.