thank you very much for your comments. as you have them, am asking some questions based on what the instructions show.
there are several instructions, for several series of models, and some have only 1 adjustment. from the post i had before, there are 2 kinds of adjustments (compression damping, and rebound), and hopefully the ones am getting fit into those. only the last series mentions both. see:
"Adjustment Procedures Independently adjustable in both compression and rebound this series racing shock absorbers offer over 140 different combinations and rebound, to finely tune the chassis for maximum performance. "
from the videos, rebound is done at the top, compression at the bottom, so this needs to get under the car, right? for both front and rear.
i think that when ordering, i need from the supplier to tell me exactly what series they are sending, otherwise i may get some of the previous series that dont have both adjustments.
and still have no idea how (or if) to reach that screw at the bottom...