I used the Hein gericke kit last year - works a treat
IIRC correctly, the order of use is something like this:-
1) Insert spikey hook thing into hole and ram in and out a few times (oooeeerrr) to roughen up the edges.
2) Smear the spikey hook thing with glue and insert in to hole again to spread the glue around
3) Smear the rubber loop with glue
4) Hook the rubber loop onto the hook and insert 3/4 of the way into the hole
5) Cut of the excess on the outside of the hole
6) Connect the gas canister
7) Re-inflate and ride home
You do get instructions in the pack - i had never used one before, and managed to repair a tyre that was already several miles past it's 'best before date' and then ride 300 miles home with no problems whatsoever.