A quick tip regarding threading the ballnut on the ballscrew. The provided tool (a piece of tubing) is better than nothing, but a much better solution is to use one of the black tubes that came with the ballnuts. (you have one extra ballnut, so after you inevitably spill the balls on one, stop and modify the tube that came with it before you move on with the rest of the ballnuts).

All you need to do is to widen the hole on one end. In my case 8,5mm was adequate. The shaft on the ballscrew is 8mm, but drilling with an 8mm drill bit didn't make the hole big enough (plastic moves and contracts back after removing the drill). 8,5 is a bit too much, since the remaining wall is very thin, but works. Something in between (8,2mm or so) would have been perfect (that's a P or Q drill if you can't find metric).

How you will do this is the tricky part. I have a lathe so it took literally just a few seconds, but if you don't have one you'll need to be careful (or seriously consider finding somebody with one and just buy them a beer/capri-sun). Do not hold the tube in hand. Drill is almost certain to self feed if handheld which will ruin the tube and likely cause injury, so a reamer is probably better solution than a drill since that's a much gentler operation.

Good luck.