I thought the same thing at first. That is until I looked at the directions. Underneath the plastic cover is a smaller steel cover. That one also needs to be lifted up. Once that is up,the mulch kit should easily slide into place.
Dave
I had the same problem. I went ahead and ordered ywo of them from the parts supplier. Unfortunately they don't have any and are on back order. Who knows when I'll get them. In the meantime, in order to be able to use the mower, I pushed a small flat washer on both sides of the machined surface of the steering column. It's working so far for me
Dave