Once you're satisfied with the inflation, it's time to glue on the final part: the luer seat. Start by inspecting the back of the quadruped and doing a dry fit. Chances are you'll have to take a pair of wire cutters and open up the holes in back a bit. The quadruped should sit all the way into the luer seat without too much manhandling. When you're satisfied with the fit, clean up the whole area that will be glued with some rubbing alcohol on a q-tip.
Take a little paintbrush and coat the whole interior of the luer seat with Sil-Poxy. Try to get a even coat so that it won't glob up in places disturbing the quadruped's fit. When it's ready, ease the back of the quadruped in and set the quadruped up in the corner between a table and a wall to hold the seat on straight. When the glue dries in about an hour, you should have a working quadruped on your hands.
Hook up your luer fittings to some lengths of hose, twist those luers into the back of the bot, and you're ready to play around. You could power it electronically using the same air system as my trefoil tentacle, keep using the sphygmomanometer pumps, or use a system you devise.