Pin Assignment in ispLEVER Classic
Found it on my own after an hour of searching. As per the website:


  How can I assign device pin out for GAL devices?
  
  The Design Planner (or the Constraint / Preference Editor) is not
  supported for GAL devices. The pin assignments can be made either in
  the HDL source code itself or you can let the software choose them.
  
  For ABEL, specify a pin number when declaring the pin.
  
  Example syntax for ABEL source pin assignments can be found in File >
  Open Examples. Then browse to Examples > SPLD > gal > mlcount >
  mlcount
  
  For VHDL or Verilog, use the attribute 'LOC'
  
  Below is an example in VHDL:
  Syntax

attribute LOC : string;
attribute LOC of SigName: signal is "P[Pin#]";

  
  Example

attribute LOC : string;
attribute LOC of out0: signal is "PA3";
attribute LOC of out1: signal is "PF8 PA2 PB3";