The hardest time I had with this clamp was the new one which seemed to have had a little too excessive glue on it. (Which ran down towards the clasp. It is in fact glued on the backside onto the hose to hold it in place, at least mine was)
I had the whole bottle in, guided the hose above the steering column, seated the hose onto the line from the heater core return to only discover I couldn't get the clasp to unsnap at all. Bottle had to come back out on the bench and had to work the clasp loose, then back in and finally snapped it undone with ease.
Was indeed a bitching moment while my sore back was telling me it was taking way too long.
The original old clasp on the return line came out a lot easier then the new one went in.