Let me add too that his behavior (besides limping) is normal. He crows all day, eating, drinking, and is still getting some from his girlshe's such a good guy. We pick him up, pet him. I just love him to pieces.
Awww he sounds like a good guy. Unfortunately, if you don't get it all it will keep coming back (I have learned). My hen drank and ate normally also, which is a good thing. It's nasty, but you need to cut an opening around the kernel to get that nasty infection out. I had to do a lot of manipulation and squeezing to get it out. Just make sure he is wrapped in a towel and is secure. You want to keep the site as sterile as possible, otherwise there is a possibility of introducing another infection. Before surgery, soak in Epsom salt, it will help loosen everything up. After soaking I clean the site and area around with betadine. Once that is done, put your gloves on and make an incision. Remember ther kernel goes pretty deep (reference the you tube video) so you might have to make multiple cuts. Also remember to breathe, not everyone is a surgeon and as responsible owners it's hard to cut into your sweet chickens foot. I sure had a hard time with it, but the infection needs to come out otherwise it can go to the bone. Once you feel you have achieved a successful surgery, bandage him up. I normally with irrigate the wound with betadine/ water mixture, then pack the wound with neosporin and use a telfapad (non stick) folded on itself (just to add some padding on the incision) and then wrap foot securely with vet wrap-- Not too tight or you will cut off circulation to area. The first couple of days it might be oozy, just keep the bandages clean and change if needed. Once the insision is starting to look better, you can discontinue the telfapad and just use regular gauze. I would keep him separated for atleast a week so he can heal and you can observe. Sometimes it takes multiple surgeries to get it all. Good Luck!
