Sounds like a euro cylinder. Does it look similar to
this? Also can you tell us if there's a name or a brand on it, cos with euros you've got half a chance that there will be spools in it... in which case you'll wanna practice on something easier first. Actually that'd be a good idea in either case cos if it's in your door and you mess something up you're gonna be in trouble.
It's not a case of just "pushing the pins down", you need to feel for the binding pin and push it to the correct position then move to the next one. Each pin needs to be pushed the correct amount, like what the key does. Pushing them all the way down will just overset them and the lock won't open because the shear line is blocked by the key pins.
