well first off forgive me for not explaining in more detail, sometimes i forget that i may not be dealing with a lifttruck tech. :o)
anyways...
first- get the wheels off the ground, best way is to find some blocks of wood ( 2x4 or 4x4 ) and put them underneath the front under the mast channel on the most outside channel under the front edge. (hardwood blocks work best because they dont crush as easily)
second- tilt mast forward till both wheels are off the ground

once you get the wheels off the ground you can release the park brake and turn the wheels and see if there is much drag on them if any. Most lift trucks have limited slip drive differential so when you turn one side it will try and turn the other side so you may feel some resistance in the carrier assy inside the differential, but outside of that you should feel a slight drag if the shoes are adjusted correctly.

one way to check this is to look under the inside edge on bottom side of the backing plate where there should be a couple of oval shaped rubber plugs, sometimes techs leave these out for some strange reason so it might just be an oblong hole, this is where the adjuster wheel is located, inside that hole. If there are 2 holes there you will have to check both of them and find which one the star wheel is located at, it will be offset to one side or the other.
Now to adjust them, most of the time a flat-bladed screwdriver will work but i find it easier to use a brake adjuster tool. If everything is in order inside there you can take the adjuster and put it up inside the hole and feel it and you can feel the star wheel. Try and turn it in one direction either up or down, if it clicks then your going in the correct direction, if it gets hard to move then that is the wrong direction. There is a metal spring loaded locking tab against that star wheel to keep it from deadjusting. Once you establish which way to turn it move it only a few clicks at a time ( i usually go 5 or so, since this is a training lesson i would go only 2 or 3 clicks) while spinning the tire. Once the shoes are close to the drum it will start to drag (this is the drag i speak of).
Now being that the differential is already putting resistance on the drive train i find that you can listen as you turn the tire and actually hear the drum start to rub the shoes, since its not perfectly round it will be hard then as you turn it may free up or visa versa once you get the drag started, if there is no drag then tighten up the adjuster till you first start to feel the drag. Then... you can find the center "free movement area" and use that as a reference point. You dont want to lock the tire down but you also dont want alot of free movement without drag. I usually put enough drag so it may take about 15lbs pressure to turn the tire. If you happen to go to far the tire may drag so much it locks up while turning, in this case you will have to deadjust the starwheel which is another lesson. This will take some tool like a small screw driver to stick up inside the adjuster hole(along with the adjuster tool) and push the locking tab away from the star-wheel so you can reverse the turn tp loosen the shoes and free up the tire. This is kinda hard to do and is a pain but it happens sometimes.
Just remember Too much drag can crystallize or burn up the shoes, this would be bad of course so pay attention on what you are doing :o)
Once you get a slight drag on the tire while turning it your done and you can do that other side the same way.

In alot of cases when i do PM's on Yale or Hyster trucks when i check the brakes i rarely ever have to adjust the wheel adjusters more than 20 clicks on either side.

I hope this was explained well enough for you to understand.
And one last thing, always remember safety first... pay attention to what you are doing and always make sure the truck is not going to move anywhere. Isolate any power sources or moving parts if they pose a potential risk of unexpected injury. Lifttrucks are great tools but they are not very forgiving when they hurt you... its usually bad.