i just finally changed the LE bladder of a contra 06' and 2 struts and what a pain in the.... here's the sequence on how i did it with help..fold LE like an accordion with talcum powder, slide the LE thru zipper having it pulled slowly, set the main intake hole on the velcro and attach collar lock ring, fold LE ends and velcro in place, pop out the sprint valves and attach rubber hoses, do the struts with same..(noticed two tight spots left and right of the main bladder) but decided to pump while shaking the outer skin to set bladder but still the same and waited 20mins. to see if any air leaking so none...as i went to the beach pumped it up with more air than at house and noticed that even at a higher pressure the LE seems to be folding a little bit...do they set after a few timeswe checked the tight spots and made sure no twists happened inside..cheers