After starting the Microsoft Visio, select the category “Sequence Chart Studio” and choose the MSC drawing template.
The SCStudio functions are available via the “SCStudio” menu and the “Sequence Chart” toolbar. Some actions are also available via the context menu (accessed by right-clicking the document or some shapes). Many functions also have a hotkey, typically with Ctrl + Alt modifiers.
The very basic mean of operation is to drag and drop basic MSC or high-level MSC stencils to the drawing and glue the shapes to each other. Every stencil provided by SCStudio represents a given MSC symbol regardless the actual shape of the stencil. You may thus freely change the format of any shape, or rotate the drawing.