Changing company currency and previous timesheets

After reading Multi Currency Accounting I still am left with a question.

We want to move our company currency from USD to RMB. We can do this in Company > currency. However, this does not convert the precious estimated costs, as they are based on the Activity Cost rate. Manually updating the rates to RMB doesn’t seem to solve this issue, as this only affects new timesheets.

Is there any way we can convert our company AND our timesheets from USD to RMB? There is too much historical data to ignore here.

Hi welcome to ERPNext

"
Is there any way we can convert our company AND our timesheets from USD to RMB? There is too much historical data to ignore here.
"

You may want to explore either of these options -

This tool Bulk Update Tool

Or export your data, make the change, then import the data back
https://erpnext.com/docs/user/manual/en/setting-up/data/data-import

You will need to do some trail and error and search the forum for ideas and user experience reports. You also may want to run a self-hosted instance to facilitate that.