What we do at my work for laying vinyl stickers/decals/etc, as well as tint, is to use water only. No soap. As said before, both surfaces need to be wet.
First, cut all of your pieces out.
Then get your car inside a garage, then close the garage door. Wind brings dust and no matter how many times you clean the glass, it will never stay clean.
Get a stand of some sort, and hang a drop light from it, such that it will shine from the outside of the glass inwards. This helps make bubbles more visible.
Clean the first glass with a solvent that leaves no residue; something that evaporates quickly. Windex works well enough. You cannot use paper towels or rags to clean. You need something that doesn't leave fibers behind.
Once the glass is clean, attach multiple pieces of masking tape to the tint on the edges. That way you have something to grab onto that prevents you from touching the tint.
Wet the glass, peel a portion of the backing off of the tint and wet it with the spray bottle too. Then start in one corner (lets say left corner for example), with a squeegee and apply the tint. Start with a 2" wide section, and squeegee the tint until all of the bubbles are out. Move on to another 2" section to the right, remove the bubbles as you apply the tint, moving the bubbles to the right. Do not go back to the left, as that side is already devoid of bubbles. Always move right, as you apply the tint, remove the bubbles. As you move to your right, remove the backing. Don't peel too much off. The longer you have the tint exposed, the more likely you will get dirt. Remove as little as necessary.
Now you may get part way, and more bubbles may form or become visible. You can take some long pieces of masking tape, and temporarily secure the tint away from the glass. Then work the bubbles out.
Once you are done, you should be bubble free. Once you are completely stuck down, slide the tint to the correct position if necessary, wetting any dry surface if necessary.
It is tedious. Having someone shining the light from behind will really help, so you get the bubbles out before you get too far. But I cannot stress enough how important it is to get in a dust free environment. Doing it on the street will never net you good results.
Buy extra tint, because you will not get it right the first time.
Hope this helps. I have had to redo a few vinyl stickers, and since they are custom ordered/made, the bosses do not like it. Luckily you don't have to worry about that.
Scott