Simple:
Follow the divine message that he brought with him from Akshardham. -> Chant the name "Swaminarayan".
What does this mean?
For all the narayans that exist in Brahman, pray to the their leader (swami) as they do,
Live like a narayan and pray to the swami and become swaminarayan, i.e. become part of him.
It is pretty simple, but very hard to become (narayan). Here is where you need to do the austerities laid down by ShreejiMaharaj, do the yoga like nilkanthvarni, be a child like ghanshyam, etc.
All the manuals, examples, and instructions have been given to him, you just have figure it out and go with it.
And stop listening to others who keep drawing devotees to become submissive to sadhus, acharayas, temples, etc. and making them gnorant that they stop thinking for themselves and give false hope that they will go to Akshardham because some leader told them.
What is wrong in being directly in love with Swaminarayan?
What is wrong in becoming Swaminarayan?
No Atma, can be Swaminarayan, because all the Atmas are created, like everything else. But an Atma can gain the qualities of Swaminarayan and get merged into Swaminarayan.
You do not need a mediator for this, but yes you should have a guide to explain it to you, but the guide should never become a god-man.
