Beside the methods described in previous answers, you can also use a free execution plan viewer and query optimization tool ApexSQL Plan (which I’ve recently bumped into).
You can install and integrate ApexSQL Plan into SQL Server Management Studio, so execution plans can be viewed from SSMS directly.
Viewing Estimated execution plans in ApexSQL Plan
Viewing Actual execution plans in ApexSQL Plan
To view the Actual execution plan of a query, continue from the 2nd step mentioned previously, but now, once the Estimated plan is shown, click the “Actual” button from the main ribbon bar in ApexSQL Plan.
Once the “Actual” button is clicked, the Actual execution plan will be shown with detailed preview of the cost parameters along with other execution plan data.
More information about viewing execution plans can be found by following this link.