Only site administrators can edit sidebars and widgets.
From edit widget links
Each widget has an "Edit Widget" link that is only displayed to logged in administrators. After logging in, reload a page on which the widget appears, and look for the links. In the Williams purple theme, there will be a blue box located beneath each widget. In the Williams Meerkat theme, there will be an orange box located on the upper right of each widget. If no edit widget buttons appear, you probably aren't an administrator.
Clicking on "Edit Widget" will take you to the widget interface, with the selected widget expanded in the right column.
From the dashboard menu
You can also get to the widget editing interface by selecting
Appearance -> Widgets from your dashboard menu.
If you don't see the apperance menu in your dashboard tools, you aren't an administrator.
Widgets that you can add to your site are on the left under “Available Widgets.” If you can’t find the widget you’re looking for, you may need to activate a plugin first. Your site’s current sidebars and widgets are listed on the right.
List widgets in sidebar
You can hide/show the widgets inside of a sidebar by clicking on the arrow next to the sidebar’s name (outlined in orange above).
Add a widget
You can add a widget by dragging it from the available widgets bin on the left, and dropping it in your sidebar on the right. The sidebar must be expanded before you can drop a widget in it.
If you have a small screen, or the the drag & drop method is inconvenient, you can click on the widget in the available widgets bin on the left, which will pop up a list of sidebars- select the one you want the widget to be in, then click the blue “Add Widget” button.
Show & edit a widget’s settings
To see a widget’s settings, click on the arrow next to its name (outlined in purple above). Make your changes and click the blue “Save” button when done.
Delete a widget by clicking on the “Delete” link at the bottom of the expanded widget, or drag it from your sidebar into the inactive widget bin (located below the available widgets bin) if you think you might use it again later.
You can change the order of the widgets in a sidebar by dragging & dropping the widgets.