You will need Fake Anim, it's not too complicated to do just a little time consuming.
realmodscene.com/index.php?/topic...nim-v060b/

You will need your video either as .wmv or converted to .wmv
Your video can be any video you find converted to .wmv

Extracting The Folder

Once you have downloaded this, you need to extract the folder to your desktop. Open the BootAnim folder, then open jukebox. This is where you will be putting the video file you want as your boot animation. There will be a few videos in this folder that you will not need. If you plan on switching back to the original boot animation you will need to make a copy of the original on your desktop.

From here you will drag your video file into the jukebox folder, it should be the only video in the folder.
Now that you have your video file into the folder, you will want to copy the BootAnim folder onto your HDD where all your other folders are. (Games, Media, Content, etc.) This can also be on any storage device.

Edit Your Launch.ini

You will need to open your launch.ini up on your computer and put a new default in it.
Replace the example part on FakeAnim to where your FakeAnim is located.

From this point, your console will boot both videos, your custom animation, and the original. You can stop here or continue to remove the original.

All that is left now, is to delete the original animation from your console and fix the timing on your custom animation.

You will now need to go into the fakeanim folder on your rgh and extract the config file from it. This file allows you to change the timing of the red screen which you will see before your custom animation.
Open the config file and change the delay to 10. or more but don't forget, the console needs time to boot before you can launch the animation. Once that's done change the Calibration in that file to 0. Now you can save this file back into the fake anim folder overwriting the old one.

The next step, you will be removing the original logo. So if you would like to keep it, do not do this.

Removing The Original Logo And Setting Up Config

You need to go into your RGH through ftp or you can use freestyle dash and find the flash folder on your RGH. If you are using freestyle dash you need to go into general settings and enable the advanced file manager in order to remove this file.

Now that you can see your files you need to navigate to the flash folder. inside this is a file called bootanim.xex. You will want to remove this file. Once you have removed the file you will have completed your task of swapping out your original boot animation to your custom boot animation. Keep in mind that doing this, you are deleting this forever until you reflash your nand with the previous one that had bootanim on it. You will want to backup your nand just in case something messes up and you need to reflash.