My son is also 5 and I sometimes see that "I know it all attitude." as well. Most of the time, I try to let those natural consequences be the teacher.
Currently, we are trying to teach him to eat with real chopsticks, not the training ones for kids. (We live in Japan so this is a necessary life skill here.) He can eat fine with the kids chopsticks, but he will start kindergarten soon and needs to be able to eat with the real ones. First I tried to teach him how to use them; Then my husband who is Japanese and a native chopstick user unlike me tried, but we were met with the 'I know how to do it attitude.' When our son failed to pick up any food, he got mad, stuck his fingers in his ear when we offered to help, and stormed off without eating. So we bought a chopstick game where you have to use chopsticks to move different shaped beans. He was super excited to play, but again we met the same frustration with our son not being able to listen to our suggestions with how to hold. One day, we just demonstrated without using any words, still the same response. Yesterday, we were filling out one of the forms for kindergarten. It had a question about if there was anything we would like the kindergarten teachers to work on with him. We wrote to please teach him how to use chopsticks. Sometimes, you just have to let someone else be the teacher and step away. My guess is that he will be very hungry on those first few days of kindergarten when they will be eating with chopsticks. I kind of feel sorry for the kindergarten teachers and other students if he is hungry. My son can be most unpleasant to be around if he is hungry. But if noone wants to be around him and he is hungry enough, he might start to see just how necessary it is that he take our suggestions. It's tough to watch though. If he gets nasty though, and throws the chopsticks down or hits something then he does get talked to and some consequence will happen (usually his playtime disappears because he doesn't want to apologize.) I simply tell him what I expect and wait it out. We have sometimes even waited it out until dinner or bathtime and then he will finally apologize. So not fun for us, but totally gets the results we wanted. He knows that I expect him to apologize for throwing or hitting. I try to talk with him about his feelings and really listen and repeat back what he says to me, and we try to brainstorm on ways to make it better next time. We do yoga to calm down. He understands that he needs to be able to use the chopsticks because he will go to kindergarten, but we haven't come up with ny good solutions so far on how to learn how.
It has been my experience with my son that the bribes and punishments really don't work well with him. We stopped doing that altogether. Now, I praise him with specific praise when he does something well or the desired behavior. I am teaching him how to read and write in English since this will not be taught at school until much later and then taught by a non-native speaker. I understand how frustrating that attitude can get. Most parents are not in the position that they need to teach a school subject to their kid, so giving that over to another person is often the better option. In our case, I step back and ask myself am I expecting too much from my son right now. Sometimes we take a break and don't practice ABCs. I yry to take my clues from my son on his readiness for reading. He loves to look at books. The other day, he picked a book of his shelf and I overheard him reading from it. He came running up to me afterwards telling me that he read the book all by himself. I took that oportunity to specifically praise him. "You worked so hard learning how to read and write the letters and now you can read that book all by yourself." Then I invited him to play ABC games with me. Use that praise to further motivate and draw the connections to the harder necessary to practice part and the outcome. Specific praise really works better than, the generic "That's wonderful. You did a good job." type of praising trap that many parents fall into. You might try using specific praise with your son's physical therapy. And I would talk to the therapist about suggestions for improving practicing with you at home.
I don't know if that helps much, but you are not alone in this stage.