Background change

[KTA]

Mark Haertl's Valentine shot:

http://www.pbase.com/pam_r/image/92966272.jpg

Before:

http://www.pbase.com/pam_r/image/92966143.jpg

seen on dpreview.com

I am wondering if someone could lead me into changing the background of an image as it was done above

[PhotosGuy]

If you want to show something that you haven't personally shot, you can just post a link to it. © issues?
IMAGE POSTING RULES (http://photography-on-the.net/forum/showthread.php?t=74718)

Try
http://av.adobe.com/russellbrown/ExtractSM.mov

This video tutorial covers some good techniques using the Extract Filter, Alpha Channels, Layer Masks using Selections, using Levels to adjust the Mask, & Blur Tool on the Mask edges.
The only issue I have with it is that he passes over using the Pen Tool, which adds needless complexity & will have the average person tearing their hair out in less than 5 minutes?
In this case, anything that he does here with the PT can be more easily done with the Polygonal Lasso Tool which takes about ten seconds to learn.
See Selecting areas in PS (http://photography-on-the.net/forum/showthread.php?t=39994) for the ins & outs of the PLT.

Similar to Russel Brown's tut:
Makeup makeover - part 1 (http://www.photoshoptalent.com/photoshop-tutorials/makeup-makeover.php?p=1)