Change multi-currency conversion from Z to Y

[Shrikanthn]

Hi List, I am planning to change the multi-currency conversion from Z to Y for one particular currency relationship only (USD to KRW). I am also planning for it to be effective from the effective date. (No need to impact the old data). In this scenario is it a reasonably simple change in the Advanced setup form exit to P0015? Do i need to change any other setting anywhere else or do i need to restate open SO and open PO or some such thing? Any advice is greatly appreciated.

Best regards
Shrikanth