Hiya - I think you can go about it one of two ways - either incorporate the core ideas from that book in your daily life in a more organic way, or get a consultant and set up a formal programme and THEY do that thinking and planning for you, setting out a programme of activities and targets at a really granular level and you just follow their instructions. Progress may be faster and more comprehensive with a formal programme (unless you're an expert in early years development with a thorough understanding of the skills they acquire at this age!) and it's admittedly easier to have someone else come up with the activities for you. However that book really helped me learn to communicate more effectively with my son and we saw a noticeable leap in progress just from our half-baked attempts to implement the approaches ourselves. He's not having conversations yet, but we can see the path to getting there now (he's almost three)
The easiest part so far, that was solely me having a go after reading that book, has been finding routines that provide opportunity to build his vocabulary (if only a word at a time!). For example, one of the first things I did was breaking down his breakfast routine step by step - "let's get your cornflakes! yay! first we need (hold up bowl, he runs toward me, says bowl, I hand it to him), then we need (hold up spoon, he runs to get the spoon, says spoon, I hand it to him), etc etc etc". He learned all the steps to getting breakfast, associated words, and enjoyed this as a game with the running back and forth and the promise of cereal!
The HARDEST part was trying to expand his play interests (the idea that expanded play offers more varied learning opportunities) because my DS is a boy who knows his own mind! At first I was trying to find play ideas myself (Connect Four for turn taking, Gruffalo toys to accompany the story as an attempt at more imaginative play, etc) and some of that worked. Now with a consultant, she brings a lot more ideas to the table, so that's been really helpful as I was running out of ideas. The only challenge now is when my DS just isn't interested - there's not a lot you can do beyond keeping on trying with new toys and games (despite the negative perceptions of ABA we absolutely do not punish DS for something as ridiculous as not playing with a new toy, even within a formal ABA programme)
We're still at relatively early days in the programme, but I'm sticking with it as I can now see we're heading to a positive place! I know you can't 'cure' autism and that's not my goal here, but it really feels like this approach is helping us get over a communications hurdle we've been stuck at for ages.