Visual Studio Code – Modifying multiple files in VS Code at the same time by using the "Workspace Search Menu"

I’m currently updating an old project in which there is a lot of files.
In those files, I need to modify some lines that look slightly the same (i.e. for which I can make a regex).

I don’t want to update each file one by one.
Therefore, in VS Code, I’m searching for a way to modify them at the same time.

I thought about using the "Workspace Search Menu" of VS Code in order to search the lines matching a specific regex through all my files.
Once I have found all the matching lines, I open my search result in editor mode to
modify those lines.
However, I don’t know how to apply my changes to the files once I’m done.

Here is my question :
"Is it possible and if so how can I do that ?"

Btw, I am only using VS Code and I don’t mind downloading some extensions if it’s needed.

Note : To open the "Workspace Search Menu" you need to press Ctrl+Shift+F in Windows & Linux or Cmd+Shift+F in Mac.

Edit : I do know how to replace each occurence of a line with something else in all files using Ctrl+Shift+H (or Cmd+Shift+H).
However in my case, the changes I want to make will depend on the line.
For example :

Before the changes :

In file a.js

let a = 2;

In file b.js

let b = "Hello World !";

After the changes :

In file a.js

const a=2;

In file b.js

const b="Hello World !";

Note that the line in a.js and b.js aren’t the same before nor after the changes.
However, we could say that they have been changed in the same way.