Paymet terms changing through T code:FB02

HI SAP

Masters

we have nearly 2500 vendors, vendor masters data Payment terms C045 (it means 45days credit) maintaining,

now our client want to change the Payment terms insted of 45 days credit 60 days credit, we changed in vendor master.

already posted documents aslo he want to change through FB02, in FB02 Payment terms field is display mode.

so can we change the field mode through T code:OB32?

after changing the payment terms field mode, can we do payment changes through FB02?

Is it correct way? is there any affect for other areas?

Plz suggest me

Thanks

Hari