While you are on your Facebook page, click on the "More" tab, which appears just under your cover image. Select Manage Tabs from the drop-down menu.
This will launch the "Manage Tabs" popover. Use your mouse to drag your tab titles to change the order.
Click Save to commit to your changes.
Remove a Custom Tab
To remove a custom you created with Pagemodo you will have to go through the Apps section of your page Settings.
From the upper-right corner of your page, click Settings, then from the left menu click Apps.
Your custom tabs will show as Pagemodo-branded apps. Click the X for the tab you wish to remove. A popover message will ask you to confirm that you want to remove the app. Click Yes.