Don’t let that bother you - make a counterfeit bird! (6,2)
I believe the answer is:
forget it
'don't let that bother you' is the definition.
I know nothing about this answer so I can't judge whether this works.
'a counterfeit bird' is the wordplay.
'a counterfeit' becomes 'forge' (I've seen this in another clue).
'bird' becomes 'tit' (tit is a kind of bird).
'forge'+'tit'='FORGET IT'
'make' acts as a link.
Can you help me to learn more?
(Other definitions for forget it that I've seen before include "Let it go!" , "ignore something" , "Not a chance" , "There's no need for apologies" , "Think no more of the matter" .)