You should first install and load the XLRisk addin and build an Excel model which you want simulate using Monte-Carlo simulation.

1. Specify the uncertainty in your model by replacing uncertain parameters with risk/distribution functions such as RiskUniform, RiskNormal etc.
2. Use the Options Dialog using the "Setup" button of the XLRisk Ribbon tab to initialize XLRisk on the active workbook.
3. Set the number of iterations either in the Options Dialog or using the iterations combo box on the XLRisk Ribbon tab.
4. Specify the simulation outputs by selecting the cells containing the model results and pressing the "Add Output" button of the XLRisk Ribbon tab.
5. Press the Run button in the XLRisk Ribbon tab to run the simulation. While the simulation is running, you can observe the progress in the Status Bar. You can also interrupt and terminate the simulation by pressing the stop button on the XLRisk Ribbon tab.

After the simulation is completed, a new "Risk Results" sheet will be created that contains the results of the simulation.

See the worked example for more details.