i cant find any info on how this is done..

Can you use hydroponic ph up/down mixed in with the water that you are feeding your plants?

Using a couple of drops of vinegar will lower the ph in your water as well as a top coat of used coffee grounds. Gardening lime as a top coat will raise ph in soil. Hope this helps.

that seems tough for a new grower to get right..

so the hydroponic up/down wont work mixed with water?

check out my buddy Jason Wilcox on youtube, search for him and look at his videos

http://www.youtube.com/watch?v=zBpLr8GhXs8

pH up and down agents are fine for adjusting the pH of the water.
Attempting to change the pH of the soil by adjusting the pH of the water is a temporary fix. It's probably easiest for a new grower, as it affects a change that lasts a few days...at which point you'll probably be watering again. So not a real big deal unless you find yourself using a lot of pH up/down which leads to salt build up in the soil.

Which is why I say, if you want to affect a long term change in root zone pH, amend the soil. My water is always adjusted to 6.5 pH.
Amending the soil is, as you mentioned, a bit of trial and error. If you follow this rule, it's not so hard to minimize the error: a little goes a long way; it's always easier to amend again than to get rid of excess.
Whatever the label recommends, I apply half and give it a week or so before re-evaluating.

Lime raises pH. Too much sets the stage for a chain of nutrient lock outs so definitely go easy.
Fe, S and peat lower pH.