Step One: Open the selected image you want to remove something from.
Step Two: Zoom In, Select Pen Tool, and start "outlining" the wanted selection.
Step Three: Close Path by returning the path to its start, Then Click on the "Path" Tab next to Layers. Right Click on Work Path Layer, Make Selection, Feather - 0 pixels.
Step Four: Now with your Item selected, Copy Selection and either paste on a new layer, or create a new document(will be sized to whats on your clipboard) and put it there!
I use this technique alot, I hope some may find it helpfull.