The layering tools are on the top toolbar. They look like this:
Move to front:
Click the item.
Click the Move to Front button and the item is brought to the very front of the design.
Move forwards:
Click the item.
Click the Move Forwards button.
Move backwards:
Click the item.
Click the Move Backwards button.
Move to back:
Click the item.
Click the Move to Back button. The item is moved to the very back of the design behind all the other items on the page.
Using the right-click menu
Click the item.
Right-click the item and the right-click menu appears. Select a layer position.