No, You don't need the code of the texture hack.
This is the code I use for my texture hacks, it is the loader, start copying from Loaders.
===Dynamic SD Loader System
*****34 lines of code
File Replacment: v2.1a[Phantom Wings]
-All patch files must be located in the pf folder as listed in the list of file directories.
Change it to gct file and put it in ur codes folder named as RSBE01.
Now you have to create a directory of folders were your going to store your texture hacks.
This is the directory private/wii/app/RSBE/pf/fighter/
then inside that fighter folder you have to create a folder for each character you want textures for. Heres the trick why so many people are doing this wrong, you have TO name the folder as the character is name is stored in the disk.
So the directory for captain falcon would look like this.
Here is a list below
Captain Falcon: captain
King Dedede: dedede
Diddy Kong: diddy
Donkey Kong: donkey
Mr. Game & Watch:gamewatch
GIGA Bowser: gkoopa
Meta Knight: metaknight
Captain Olimar: pikmin
Ice Climbers: popo
Zero Suit Samus:szerosuit
Toon Link: toonlink
Green Alloy: zakoball
Yellow Alloy: zakochild
Blue Alloy: zakogirl
Red Alloy: zakoboy
After you've done the folders for the characters you want texture on go to some texture hack site like Stacksmash and grab some cool texture.
To download a Stacksmash texture you have to look for "Released Content".
When its done downloading grab the file and put it in your captain folder (example) and rename it to "fitcaptain00.pcs" (this is for every character you have to put fit and the name of the folder) and then the number of the costume the texture will be replacing.
When you did it insert your SD into your Wii and launch up Gecko OS and it should work.
Here is the link of the guide I used http://www.smashboards.com/showthread.php?t=225642
Hope that helps you