Yeah, I has to tinker for a little while too, but there's no special tool or technique. It's just a little awkward.
Like Daggo said, you just need to make sure everything is seated properly and then apply pressure to the clip. If it's taking a lot of force or the clips appear not to reach where they need to go, it's not on right.
Regarding the clips that are hard to reach, maybe just try a large flathead screw driver. I remember thinking that it was good I didn't have large hands.