Login to your Shareaholic account and select a Site Profile from the My Sites dropdown at the top of the page.
From the Apps page, scroll down to the Share Buttons box in the 'Social Settings' section and find the entry for the Share Buttons you wish to edit. Then, click on the settings button to access its settings.
In the Layout tab of the Share Buttons Settings window, select your desired alignment from the buttons next to Alignment. You will see a live preview of your changes on the righthand Preview pane.