First change the Max Level
Search: 807834077628
Change to: 807834FE7628 for lvl 255
Then with ultra edit search for the Address: 000e8590h
Change the second instance on the line which has
00 28 6B EE (4000000000exp)
to a new exp value, to do it open Hex Workshops base converter and set it like this:
Byte Order: Intel
Data Type: Unsigned Long
Insert a decimal value of the new exp u want like 2billion instead of 4billion and the value will be converted into hex.
After knowing the hex change 00 28 6B EE to the new one
This will be the exp which will be applied on all the other levels over level 51
There is no way to give a different exp for each level over 51