We need to change the existing BU and LE name to new name

Summary:

We need to change the existing BU and LE name to new name If we can change the Old legal entity name With new name.

Content (please ensure you mask any confidential information):

We need to change the existing BU and LE name to new name

If we can change the Old legal entity name With new name .can you please help us on following Query
1-Can we Update Old legal name With New legal entity name.
2-Changing the legal entity name will have any financial impact from FIN side ?
3-Is it possible to keep the old legal entity name for all the existing old transaction, client want this new legal entity name to be appear only for new transactions.