no problem. theres not really much that can go wrong unless you strip or cross a thread. so:
a) if you take the cups off and clean/grease make sure they spin back on nice and easy and the thread is seated right before you crank them with the bb tool.
b) don't overtighten the crank pinch bolts. again it's just alloy, and is easy to strip a thread out, then your off side crank becomes a paper weight.
c) if you don't over tighten the preload then the offside crank should come off pretty easy. however as you didn't assemble it, it may be over tight and you need to slip a flat head screwdriver between the crank and the cup bearings to ease the crank off.
d) when you are putting it all together, i can't remember what the torque required is on the pre-load cap, but it's not much, maybe 4Nm from memory. as soon as you start side loading the bearings by over tightening you'll notice the cranks won't spin freely. again i do this by feel and always make sure the cranks are rotating nice and freely before torquing the pinch bolts. sideloading the cups isn't the end of the world, just reduces the functional life of the bearings, so while you want to get it right, it's not like say stripping out the pinch bolt thread.
--brett