Changes the last word -- 'dust', oddly (6)
I believe the answer is:
amends
'changes' is the definition.
(amending is a kind of changing)
'the last word dust oddly' is the wordplay.
'the last word' becomes 'amen' (I've seen this before).
'oddly' indicates alternate letters.
The alternate letters of 'dust' are 'ds'.
'amen'+'ds'='AMENDS'
(Other definitions for amends that I've seen before include "Makes minor improvements" , "Make these to right wrong" , "Atonement" , "They're made to compensate" , "Make them to compensate" .)