It should be easier at this age as he understands, if you have him on diapers or pullups ,remove them , get him, in fact let him choose some big boy underwear at the store .With out making a huge issue of it tell him , 'now you have big boy pants so go pee in the toilet,' let him be in control himself, you can remind him if he doesn't remember ,but keep it casual and low key.Sometimes parents make a big deal of it and it creates anxiety at going . Don't follow him into the bathroom let him have his privacy,in fact less words the better .as I say at this age he should understand more , if he want to go poop , leave the paper handy for him, if he doesn't wipe well you can remind him to wipe better and wash hands .least said is better nonchalance is good .good luck