Use this tutorial created by trickvilla to remove unwanted objects or obstructions from an image using Photoshop CS5 new feature called: content aware fill.
One of the more cutting-edge features delivered in Photoshop CS6 Beta is the brand new Content-Aware Move Tool. The concept of this tool is that you will be able to select objects in your image and move them around and Photoshop will do all the edge work and re-blend your object (face, person, building, car, etc... etc...) into whatever part of the image you move it to.
The tool is a far cry from being perfect and often time's takes a little tweaking and playing with to get a great result.