Changing GL Class

Hi I am using JD 9.1

I have the order which has completed the sales update. now if I want to change the GL class, what are the issues I could face??

I have read the white paper. there it was written that

The G/L Class Code is also stored in the Cardex/Item Ledger (F4111) file. If any transaction are done against an Item, the previous records in Item Ledger (F4111) will all have the 'old' G/L Class. If any As Of Processing (F41112) was done, any update using the 'new' G/L Class will create a separate record as the GL- class field is a key in this file.