if your coilovers are like mine than theres a lower collar-(C) that you lossen then actually turn the whole shock body down or up to height,then lock (C) back down.
Yeah those are designed different than mine so don't listen to me lol. I'm totally not trying to sound like a dick, but I recommend following the instructions in that manual. Tein should know their own stuff well enough to know how to have it properly adjusted.