With electronics workbench, you have to use the oscilloscope. Just connect a "wire" from oscilloscope to output of your modulator and that should be it.
For pspice (I am assuming that you have ver 9.XX or so), place a voltage probe ("voltage/level marker") on the output of the modulator and then do a transient analysis (set start time and end time (longer the end time -> slower the simulation)). The transient analysis (time domain) is located in simulation profile (e.g. click on "New Simulation Profile"). If you don't place the voltage probe then you can still select later your inputs or outputs from the simulation/graph window (e.g. "Add trace..." option).
If you do indeed have the newer versions of pspice, then to create a schematic you have to create a project. Just click on "File->New->Project..."
then type in the name of the project and select "Analog or Mixed A/D" option and you are set. You might be prompted by another window and there specify "Create blank project"