you can use the Identity class to update the new name , all objects where identity is referred is based on id so there won’t be any issue for assigned links , role , entitlements etc.
depending on how many users you have in the environment you need to write efficient rule to achieve the rename
- recache the identity object once work is done
- conically context.commitTransaction() i.e. do not commit the transaction on each identity update as this take time to update in database so best would be commit transaction after 50 or any other number of identities are updated
identity.setName(newStandardName);
context.saveObject(identity);
context.commitTransaction();