Take your original image and hit Ctrl+A (Select All) then Ctrl+C (Copy All) and finally Ctrl+N (New). When given options for the new image select 300dpi with a transparent background and then OK.
In your new image hit Ctrl+V (Paste).
Using the Magic Wand Tool (the default setting of 32 for the Tolerance is fine) and with both 'Anti-alias' & 'Contiguous' click on the areas you want to remove. You can select additional areas by holding down the 'Shift' key while clicking the Magic Wand on other areas.
When you selected the areas you want to remove hit the Delete key.
Once done removing all of the parts you want save it as a .psd.
And remember...the larger the image is that you start with the better your end result will be.