AX 2012 ---- Updating already existing record using Excel

Can any one explain how to Update already existing record in AX 2012 using Excel

How to update AX record using excel Add in for existing record

Is there any way to update the existing record in AX2012 through Excel upload

it depends on the record - customer, product etc., Select the record in excel, make a change and publish the selected. In most cases, it will update. there could some restrictions.