Ordering a change to part of US border (3,6)
I believe the answer is:
rio grande
'part of us border' is the definition.
'rio grande' can be an answer for 'border' (part of the US-Mexico border). I am unsure of the 'part of us' bit.
'ordering a change' is the wordplay.
'change' indicates an anagram.
'ordering'+'a'='orderinga'
'orderinga' is an anagram of 'RIO GRANDE'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for rio grande that I've seen before include "US-Mexico border river" , "Waterway rising in Colorado" , "American flower" , "Great river bordering USA and Mexico" , "US/Mexican border river" .)