The easy part: create a form with a SmartPartPlaceholder on it.

Second: provide a property like this:

public UserControl SmartPart
{
    get { return (UserControl)smartPartPlaceholder1.SmartPart; }
    set { smartPartPlaceholder1.SmartPart = value; }
}

Third:

From within a presenter make a call like this:

internal void EditCompany(int id)
{
    CompanyDetailView view = WorkItem.SmartParts.AddNew<CompanyDetailView>("CompanyDetails");

    SmartFormBase frm = new SmartFormBase();
    frm.SmartPart = view;
    frm.ShowDialog();

    WorkItem.SmartParts.Remove(view);
}

This will display your smartpart inside a normal Windows form.