Google Chrome

• 1). Open Google Chrome and then click the wrench icon in the top-right corner.
  
  
• 2). Click the tab labeled "Personal Stuff."
  
  
• 3). Click "Reset to Default Theme" to remove the current theme from the browser. To use the theme again, it must be downloaded.
  
  

Mozilla Firefox

• 1). Open Mozilla Firefox.
  
  
• 2). Click "Tools" from the top of the Firefox window.
  
  
• 3). Click "Add-ons" from the Tools menu.
  
  
• 4). Click the tab labeled "Appearance" in the Add-ons window.
  
  
• 5). Click "Remove" beside the theme that you would like to remove.
  
  
• 6). Click "Restart Firefox" to restart the browser and complete the removal.