first off..
you need to edit
\conf\battle\client.conf
max_lv: 99
aura_lv: 99
\src\map\map.h
#define MAX_LEVEL 150
if your server is in renewal mode, edit
trunk/db/re/exp.txt
if it is not renewal mode, edit
trunk/db/pre-re/exp.txt
format
//Experience tables format:
//Max Level,Class list,Type (0 - Base Exp; 1 - Job Exp),Exp for Lv 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98
// Supports baselevel up to 1000 and joblevel up to 255 (except Novice/High Novice)
edit the Max Level part