How do I unstick a glass dome on a ceiling fan to change the light bulb?

We have a ceiling fan with a light and it burnt out. Now I cannot get the glass dome off in order to change the light bulb. Anyone have any suggestions on how I can get it unstuck? It’s a Harbor Breeze
52″ Armitage Hugger Ceiling Fan (Model: CC52WW5C). Here’s a link: http://www.lowes.com/lowes/lkn?action=pr…