knock sensor help

have a 2005 silverado with 5.3l. had code p0332 so i went to change out the knock sensors. front one came out just fine, the rear one however was completely rusted up. the hex on it was gone. no way of removing it. took the valley pan off, yes kind of forced it off but wasnt too difficult as the body of the sensor broke off the threads. not here is the problem. the threads of the know sensor is so rusted in that the port it threads into broke off.



ive seen where people have done sensor relocation to front of pass head and driver side head above manifold. if i do that can i leave this port as in and put a solid valley pan on like the delete kits? please give me some advice on what to do next.