General Motors has over 4,000 service departments at its dealerships and all will be busy in the weeks ahead replacing ignition switches.

G.M. has started mailing recall letters telling owners of effected vehicles about the repair procedure. They are instructing them to set up a time to get the work done. Officials figure it will take about 90 minutes to complete. However, they are saying it could take longer, depending on how many vehicles the dealership has to tend to at that time.

In all over two million vehicles are involved. Officials say the switches could go from the on to the off position without notice.  It's been reported the defective part has been linked to a number of crashes and at least 13 deaths.