How this solution is put into place, fully (4,3,2,6)
I believe the answer is:
from top to bottom
'how this solution is put' is the definition.
I know nothing about this answer so I can't tell whether this works.
'place fully' is the wordplay.
I cannot quite see how this works, but
'place' could be 'top' (top is a kind of place) and 'top' is located in the answer.
This explanation may well be incorrect...
'into' is the link.
Can you help me to learn more?
(Other definitions for from top to bottom that I've seen before include "As this answer will be written" , "throughout? - with 17d" , "unique as this grid entry?" , "Absolutely" .)