Once you have selected a taxpayer in the portal, you're able to amend the standard layout of your summary dashboard screen.
Click on the Edit Layout button on the right hand side of your screen and your layout will become modifiable.
Just click and drag the boxes to adjust their size or location and when you are happy return to the right hand side and click on Save Settings.
Note that adjusting your layout on one taxpayer will change the layout across all taxpayers you manage.