Alternative image editing directly in WordPress. Replaces the original image editor.
Unzip the zip file to /yoursite/wp-content/plugins/
Set the directories /yoursite/wp-content/plugins/php-image-editor-lite/editimagesoriginal/, /yoursite/wp-content/plugins/php-image-editor-lite/editimagespng/ and /yoursite/wp-content/plugins/php-image-editor-lite/editimagesworkwith/ to read, write, and execute permissions.
If you already haven´t done it, set your own image directory, subdirectories to read, write, and execute permissions. For example /yoursite/wp-content/uploads/
Important! CHMOD 777 ain't secure. You could try CHMOD 755. Read more at: http://codex.wordpress.org/Changing_File_Permissions