knock yourself out
US /nɑk jərˈsɛlf aʊt/
UK /nɑk jərˈsɛlf aʊt/

1.
leef je uit, ga je gang
used to tell someone that they can do something if they want to, even if you think it is not a good idea or will not be successful
:
•
You want to try to fix the car yourself? Sure, knock yourself out!
Je wilt de auto zelf repareren? Ga je gang, leef je uit!
•
If you think you can finish all that work by yourself, knock yourself out.
Als je denkt dat je al dat werk zelf kunt afmaken, leef je uit.