Here is a guide to remove the shopping, music, photos, gwibber and video lenses on Ubuntu 13.04. You can remove the lenses using command lines in the terminal window.
To remove the lenses open a terminal window (press Ctrl+Alt+T) and copy+paste the following line:
sudo apt-get remove unity-lens-shopping unity-lens-music unity-lens-photos unity-lens-video
If you don’t want to remove all the lenses but just one lens copy+paste one of the following lines:
sudo apt-get remove unity-lens-shopping
sudo apt-get remove unity-lens-music
sudo apt-get remove unity-lens-photos
sudo apt-get remove unity-lens-video
When the lenses are removed you can close the terminal window.