Update:
New update changes


My method of this was using the the original Japanese script for the format of the name then using a combination of the Viz manga, Kanzenshuu.com,
Steve Simmon's translation for the DVDs, and Mistare Fusion and Geekdom 101 on YouTube as a reference.

Then I use my knowledge and the feedback I have been getting to make
corrections.

I followed TechnoSyndro's method for his mod for Dragon Ball Z Kakarot. For instance, I don't use honorifics in my translation so you won't see "sama", "san" or "kun" for the most part. 
 
I don't use fan terms like "Zenkai boost" and "Buuhan" and


Techniques:
For the Earth martial artists, I keep most of their moves in Japanese to separate them from all the alien fighters who tend to use English for
their attacks
Eg:
- Special Beam Cannon -- 魔貫光殺砲 --  Makankōsappō
- This also includes names that are not called out like: Burst Rush --> 爆裂ラッシュ --> Bakuretsu Rush
- For Super Kamehameha which is usually called out as Chou Kamehameha I left it alone
- Generic  style techniques like Full-PowerEnergy Blast Volley (フルパワー連続エネルギー弾) I also left alone
*One Personal Change I made was changing Super Saiyan 2 Teen Gohan's "Super Kamehameha" to "Motionless Kamehameha" like in Dragon Ball FighterZ. This is because I feel it makes the move more unique to him.

Character Names:
I mostly followed the template for the Japanese script for Dragon Ball Sparking! Zero and Dragon Ball Z Sparking! Meteor (Budokai Tekaichi 3).

-I kept things like “Goku (Z. End) and added the family name Son to him and his family.
- Master Roshi was changed to Kame Sen’nin, but when his students talk or refer to him in in-game dialog, I made it so that they refer to him as Muten
Roshi.
- At one point, I wanted to keep the Android name out of laziness but decided to edit it to say Artificial Human No.__.  
- For Artificial Human No. 13, I changed the term fusion to Union to better reflect the Japanese name 合体13号 (GattaiJū San-Gō)
- I made all Buus read as Majin Boo (__) and their version.

There are some personal changes that I made:
-Vegetto: Super Saiyan God Super Saiyan now is Vegetto Blue in the same vain as Super Vegetto (I haven't figured out how to remove subtitle from his name)
-Cell: Perfect Form was Changed to Cell: Complete Form to separate it from Perfect Cell
-Super Zarbon is now Zarbon (Transformed) like in Sparking! Meteor
-I removed titles from characters such as Captain Ginyu and Lord Slug but, added some like Dabura to Demon King Dabura following the convention
set by Dragon Ball Z Sparking! Meteor.
-I don't use straight Romanization of the Japanese script. So you won't see names like "Torankusu", "Saiya-jin" or "Oozaru"
-I also kept with the official name so while I think "Super Saiyan God Super Saiyan" is stupid, I didn't change it to "Super Saiyan Blue"


Terms
I made changes to terms in the script of the game that will show up on the main menu, Episode Mode, and subtitles in-game 
-I changed all instances of Shenron to Shen Long
-World Tournament to Tenka'ichi Budokai
-Other World Tournament to Other World Budokai
-Power level to Battle Power
-Senzu Bean to Senzu (It's redundant)
-Power Pole to Nyoibo

Other Changes
I made a few edits to the script when I noticed it. 
-The line in one of Piccolo's where he says "Begone" I changed it to "Go to Hell"
-The line when Kid Trunks is talking to Vegeta (Z. End) where he says "No Cap" I changed it to "Really"

And other little changes here and there


If you have any questions or comments feel free to message me and I will try to address them

Also, the mod only works for the English version