Not sure what the "boot scale" is.
Originally Posted by SkierXMan
By forward pressure you mean the front reading on the boot scale right?
Also I noticed on the LD12 on the front plate near the toe piece there is a sliding dial(looks like a tank track) that can be moved with the thumb, what is that?
Both the toe and heel binding component have a numbered scale. That indicates your DIN setting. If you don't "absolutely know what DIN setting you want", then you need to take it to a shop. After you set the DIN for both toe and heel, attach the toe and heel pieces to the rail and attach the rail to the ski, THEN you put you boot into the binding and close the lever and check the UN-NUMBERED ruler-like thing at the back of the binding. When the boot is in the binding, the edge of the binding should fall withing that scale. When the boot is out it will fall somewhere outside of the scale.
If you attach the bindings to the rail based on the sole length of the boot (usually on the sole of the boot) then the forward pressure will almost always be right. If it isn't within the scale when the book is clamped in, then you need to adjust the attachement point for either the heel or the toe by one mark (2.5 mm) at a time.
SUMMARY: Your original question is yes, this is pretty easy. However, some of the other questions (such as not understanding the AFD or the DIN guages) makes me say you should take it to a shop.