It might be cheaper and faster to just buy a socket to replace the damaged or missing socket because Kobalt will charge you shipping for the replacement socket.
https://www.socketsforlife.com/how_it_works
If you ever lose a socket from your Kobalt set simply call 1.888.3KOBALT and follow the "Sockets For Life" prompts. Be prepared to provide the following information:
Name
Mailing Address
Socket set or item #
Payment information for shipping charge
Shipping and handling charges do apply for each socket ordered through a "Sockets For Life" claim. Shipping and handling charge is per socket. You will be asked to provide credit card payment information before your order can be completed. The shipping & handling charges are as follows:
$4.95 - 1/4" drive, 3/8" drive and 1/2" drive sockets
$5.95 - Impact sockets
$6.95 - 3/4" drive sockets
$5.00 - Additional charge for each shipment to Canada
Once your credit card transaction is complete an order will be created and your socket will be shipped direct to you.