Not quite that simple. You need to be rooted.
To use Bootanimation.zip
Using the root explorer, navigate to system/bin
you will be working with 2 files.
*First find a file named System/Bin>"samsungani" (no file extension) and delete or rename it (ex samsunganiBAK)
Secondly find a file named System/Bin>"bootanimation" (also, no file extension) and rename this file to "samsungani" without the quotation.
Get the bootanimation.zip file that you want to use (or create your own)
Unzip it to verify a little information is correct
Open the desc.txt file > you should see something like this (numbers will vary)
700 1116 18
p 1 0 part0
p 5 0 part1
Whatever bootanimation you use, make SURE that the number directly after the "p" is NOT 0 otherwise you will enter a never-ending loop.
Put in System/Media