Time to stick spring chicken in that case (4,4)

'that case' is the definition.
I don't know anything about this answer so I cannot judge whether this works.

'time to stick spring chicken' is the wordplay.
'time' becomes 't' (abbreviation).
'to' says to put letters next to each other (I've seen this in other clues).
'stick spring' becomes 'well' (I can't explain this - if you can you should believe this answer much more).
'chicken' becomes 'hen' (hen is a kind of chicken).
't' put after 'well' is 'wellt'.
'wellt'+'hen'='WELL THEN'

'in' is the link.

Can you help me to learn more?