I know you said you’re not a fan of books, but @UnicornPorn used the same book as us which seemed to work pretty well. I’d go so far as to say avoiding the book and asking us about things, because there were bits of the book that made my other half feel inadequate too (like suggesting that if they aren’t out of nappies by a certain point they’ll need therapy in later life. WTF?!?!)
We did it in the summer and let Jimbo run around in the garden in the nude, asking him regularly if he needed the loo and encouraging him onto the potty. Tbh, if he’s already using a potty with pull ups, you might find that just putting him into pants will do the trick. The first few weeks Jimbo was very conscious about “having an accident”, and although that never happened, I think it was his concern about it that meant that he didn’t and he got used to potty training pretty quickly.