In order to change the xp for next level you need to go to: l2f.gameserver.model.base.Experience.java
This tool will ease your life: http://www.mediafire.com/file/qygpjy6evn9wqlc/Xp+For+Next+Level.exe
When finished coppy from xp.txt into the experience.java.

Created by me

 

(Pack Based: StormDC)

Virus Total: https://www.virustotal.com/en/file/1cd91430849b7203d79257cb000db04a9a78523819f995df74e188d60b8843f5/analysis/1491138246/

Dude, im sorry but... Its easier to set the new exp in the Level array instead of

1. open a program
2. set the value
3. click a button
4. go to the folder
5. open the file
6. copy the index
7. open Experience.java
8. paste -> compile.

Make something usefull and not any idea that you thinking

it just creates the xp faster so u can c/p to win time

seems like your weed is rly good...