There are several plugs in the equipment that are normally removed during the winterization process. My pump for example has two plugs that screw on and off, I also have a plug on the bottom of my DE filter that is unscrewed for the winter. You will get familar with this plug during the cleaning process as I am sure you will be opening your DE filter and cleaning your filter grids during or after the cleaning. I keep all of my plugs in the pump basket so they are all in one place and I can easily find them.
If the pool was properly winterized the pipes should have been blown out, plugged, and anti-freeze put into them. There should be a rubber plug or stopper in the returns inside the pool (this is where the water returns from the equipment back into the pool).
In my pool I have two returns which are placed in the shallow end by the steps about 2 feet or so down.
My skimmers have two holes in the bottom, the one that leads to the pump gets a rubber plug and the other gets plugged with a Gizmo which is a long plastic tube that screws into the hole. This allows the ice to compress the Gizmo instead of placing a lot of pressure on the skimmer walls.
So all this means that you will most likely have to reach your arm into the dark dirty water to search for and remove the plugs if they exist.
Once you get the plugs back into your equipment and the plugs out of the pool your pipes will still be mostly filled with anti-freeze and air. I take a garden hose and fill my pump basket for several minutes to put water back into the pipes, this is also called priming the pump. I will then turn the pump on which will immediately pull all the water I just put in, sometimes this is enough for the pump to prime and start pulling water from the pool, however in most cases I will have to repeate this process several times.
If you do decide to just drain and re-fill you can always check the water table in your area by using a post digger to dig to the depth of your pool and monitor it for few days to see if it fills with any water.