I too have ordered & received a replacement lower shelf for our dishwasher. It also came with these two tines & NO DIRECTIONS.
From reading your customer questions, others have had to order this clip (#99001436) which I have ordered & received. My husband cannot figure out how to attach the tines with this clip. Do I need to order another clip? But where does it go?
Please send a picture diagram to attach the clip!
Answer Diane, You will need two(2) tine clips  to install the tines. Using the parts diagram as a reference, The curved palstic side of the clip will face away from the tines. you'll align the clip in the bottom of the rack,slightly to the right of the bottom wrungs and slide the clip to the left until the clip on the bottom right end of the clip snaps and locks around the wrung. The clip on the bottom left is an open clip (like a fork) and will move into position and encircle the wrung when you slide the clip into the proper position. Then you can snap the tines in position on the upper clips of the tine clip. These are delicate components, and you need to be careful installing them.