I'll add this info - first up, don't use the above method of spring attachment, as the two outer springs are doing most of the work, and the centre one is pretty much redundant. Check this video for an easy, pretty well foolproof setup which allows full trem use, both up and down in pitch. I back off all screws a bit, securing the bridge baseplate to the face of the guitar, not just the inner 4.
This trem setup is not for everyone - some screw the claw all the way in, and don't let the trem pull up in pitch - whatever works for you I guess. The updside of that approach, is that if you break a string when playing, the other strings don't go out of tune, but I figure if I've got a spare guitar handy (who doesn't?), I'll take the first trem setup every time, as for me, it feels much better/easier to use.