Changeover in Financial Accounting (FI-GL/AP/AR) 
Purpose
The system changes over all data in the General Ledger (FI-GL), Accounts Receivable (FI-AR), and Accounts Payable (FI-AP) application components
including all dependent value, currency and exchange rate fields. The quantity of data to be converted is calculated as per R/3 instance=client. You cannot limit the amount of data selected.Process Flow
The following graphic shows the process of local currency changeover in Financial Accounting:

For more information on this topic, see
Changeover Procedure in Financial Accounting: Process Flow