Hi, you haven't mentioned the size of the pot relative to the tree or rootball, which would be helpful. Putting a just dug pine straight into a pot is pretty tricky at the best of times, let alone for a newbie, and I mean from the point of view of taking proper care of the tree, not just the mechanics of wiring it in. Depending (so much) on the nature of the root spread, direction, mass, etc., you would either use wires coming straight up from the holes, through the plastic canvas, and wire them around large surface roots just once or so (then either cut them or get them back down and out there (around a fat twig to hold them), but if the tree and roots are small, I'll often loop around the trunk from above in 3-4 directions, bring the wire down over the pot edges and tie them off under the pot... not pretty, but less harmful to the tree and more of a good anchor if you balance the loop tightnesses. I wouldn't wire around internal roots though.