Open Assembly

(Standard Interface) File Open Assembly            Shared Dialog Box
Opens an assembly in the current session.
 
For the option:
Do the following:
Assembly Name
Specify the assembly you want to open.

Tips on Entering File Names in Text Boxes.
Variant
Select one of the assembly variants defined in the assembly file. If the assembly does not contain any variants, this option menu will be disabled.
Open all subsystems in session
Select this toggle if you want to open every subsystem referenced in the assembly file, regardless of the selected assembly variant. If the assembly does not contain any variants, this toggle will be disabled.