Change the last word, last bit of record (5)
I believe the answer is:
amend
'change' is the definition.
(amending is a kind of changing)
'the last word last bit of record' is the wordplay.
'the last word' becomes 'amen' (I've seen this before).
'last bit of' says to take the final letters.
The last letter of 'record' is 'd'.
'amen'+'d'='AMEND'
(Other definitions for amend that I've seen before include "Correct or alter to improve" , "Modify, correct" , "Ameliorate" , "Put right" , "Correct error, make minor alteration as to writing" .)