Replacing element from a specific position at a file in c++

I am facing a logic building problem. let suppose i have following data in txt file:

David The Angel 20-04-2019 [newline] Bilal Learning how to read 20-04-2019[newline] Sarah The subtitle art of not giving the fuck 20-04-2019

Now i wants to change the date of 2ndline from 20-04-2019 to 25-04-2019 then how can i do it ?