There's no toolbar button that will remove the commas. You can add the
Style box to one of your toolbars, and select the Normal style from that.
To add the Style toolbar, right-click on a toolbar, and click on Customize.
In the Customize dialog box, click on the Command tab
Click on the Format category
Drag the Style dropdown box to one of your toolbars.
Close the Customize dialog box.
Select the cells that you want to format
From the Style dropdown, select Normal.