SAP Note 105621 -- Hiding Cost Conditions in Sales Document

dear experts:

i am facing a issue regarding SAP Note 105621. in this note it says we need to implement user exit

USEREXIT_FIELD_MODIFICATION

USEREXIT_FIELD_MODIFIC_LEER

USEREXIT_FIELD_MODIFIC_KZWI

USEREXIT_FIELD_MODIFIC_KOPF

USEREXIT_PRICING_CHECK

and create 2 new Include ZZAUTH01, ZZAUTH02.

my questions are:

1. are these user exits listed above in program LV69AFZZ?

2. I set break point in these user exits, but none of them stop the process when i run t-code VA02.

i am confused here, could anyone tell me how to get into these exits when run VA02?

THANKS.

Hongtao