Modify the home screen of OS X is not new, just not necessary, but if you want to do can.You just need to know the exact path of the image using the system for that screen. This is in the location /Library/Caches/com.apple.desktop.admin.png. Any image that we believe or we download Internet’ll just save it with the name com.apple.desktop.admin.png and replace. So easy and fast. Yes, make a backup of the original if you want it back at some point. From now on the boot image may be more to your liking.
Sure it’s not the only change we could do if we just want to change the apple logo by your own will do something similar. Create an image in .png format with a size of 428×428 pixels. Then we will keep four copies with the following name: Apple.png, email@example.com, apple_s1.png and firstname.lastname@example.org.
With these four files created we go replace the existing files. Again it is important to keep a copy in case you want to revert to the original.