To add an assembly to Blue Integrator Explorer, expand the Static Configuration section, then expand the Assemblies subsection. All currently defined assemblies are shown in the right pane. To add a new assembly to Blue Integrator, click the Add Assembly… button at the bottom of the right pane:
This will display the Select Assembly dialog, which allows you to select the assembly DLL file from the list displayed. Either double-click on the assembly to be added, or highlight it and click Open
The selected assembly will be added to the assembly library and appear on the list in the right pane of the Blue Integrator Explorer.