The beavers help put up an icelandic tent
Before the meeting start to erect one or two tents and just put up the ridge pole and the main guy ropes for these.
As beavers come outside start by talking about canvas tents - how once inside you don't touch the canvas etc. Teach them how to lace the doorways and get them to do this - it calms down excitement levels.
Show them how to bang a peg in safely - the angle the peg goes in and how to position your legs so the mallet doesn't hit the legs.
Get the beavers to pitch the rest of the tent (not the brailing pegs) and then go inside the tent.
Teach them how to remove the pegs - side to side - and how to clean them so the tent is ready for the next group.