The Power Solids product for Rhino has 3 commands, which can be accessed by typing in the command name or using the nPowerSoftware menu. The commands names are "PowerBoolTree", "PowerFillet" and "PowerShell". The Power Booleans product uses the "PowerBoolTree" command in Power Solids with with additional enhancements to produce Meshes from NURBS and to provide Booleans on MESH objects. Details about how to use these commands is documented here as follows:
"PowerBoolTree" - Boolean Tree that has Solid Booleans, Merging, Automatic Operand Filleting, and a Persistent Tree History.
"PowerFillet" - High-End Filleting tool with Variable Radius Fillets and the ability to Handle Large Radius Fillet Cases.
"PowerShell" - Shelling and Offsetting Tool
Installation:

The "nPower" menu should appear on the Main
toolbar and the Power Solids
ToolBar should also appear. The ToolBar buttons are from left to right:
PowerFillet, PowerShell, PowerBoolTree.
NOTE: The first time you run you
will need to install the plug-in using
the Rhino Plug-in Manager. Select the "Tools/Plugin Manager" from the
main menu and
select the "Load" button in the Dialog. There should be a
"PowerSolids*.rhp"
file in your ".../Rhinoceros/Plug-ins" directory that can
be selected for
loading.
NOTE 2: To see the ToolBar you will need to load the PowerSolids workspace.
From the main menu select "Tools/Toolbar Layout...". In the
"Toolbars" dialog
"File/Open" and select the Power Solids workspace "PowerSolids.ws".
If you
have the tool bar loaded and don't see the tools, make sure there is a check
mark in the PowerSolids toolbar on the bottom window when you select
PowerSolids in the top window of the dialog.
NOTE 2: This plug-in is an "auto-load" plug-in. This means that you
will not
see the menu until you invoke the command the first time during the session
and force the plug-in to load. You can do this by typing one of the
commands
into the Rhino command line "PowerFillet", "PowerShell", "PowerBoolTree" or
selecting one of the commands from the Power Solids Toolbar.