Live or die, that's come out nicely (5)
I believe the answer is:
dwell
'live' is the definition.
(I know that live can be written as dwell)
'come out nicely' is the wordplay.
'come' becomes 'do' (synonyms).
'out' means to remove the last letter.
'nicely' becomes 'well' (I've seen this before).
'do' with its last letter removed is 'd'.
'd'+'well'='DWELL'
'or die that's' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for dwell that I've seen before include "Focus attention (on)" , "Inhabit" , "Abide, reside" , "Reside - linger" , "Live (in a place)" .)