1. Navigate to the following folder: 
Macintosh HD/Users/Your_User_Folder/Library/Application Support/com.marketcircle.Daylite4/Plugins

Please note: On Lion and Mountain Lion systems the "Library" folder is hidden. In oder to access it click "Go to" in the Finder menu and hold down the [alt] key. The "Library" folder is now visible.

2. Select and delete the appropriate plugin.
3. Restart Daylite