Step 1: To search for an image with a clear background:

• Open a Google image search

• Select the tools button (under the search bar) to open more options

• Select the colour drop-down menu

• Select Transparent

• Right-click on the image and select 'save image as...'

• Save the image to your desktop.

Step 2: From the top toolbar:

Select the 'Insert' drop-down menu and select Decal.

From inside the new window that opens, select 'Insert from my computer....'

Locate the file from your desktop and select 'Open'

Step 3: From the insert decal window:

Select the face (surface) where you would like to apply the decal (sticker).

Use the arrows and rotation handles to move the decal into the desired location and press 'OK' to complete the placement.