How to show or print all the parts in an OrCAD library (OLB) file?
After extensive trial and error, and some Google work, I found the solution:


Start Orcad Capture.
Select menu File => Open => Library, and select the .OLB file. 
Double click the part symbol (AND gate) to open first part of symbol.
Select menu View => Package to show all parts in package.


Then printing will show all the parts each in a box.