Replace line breaks

I am using visual studio code for several things. Everything is working fine, but I cannot get one specific thing to work.

I need the ability to remove line breaks from the text.

Example:

first line
second line

Should become:

first linesecondline

Since a recent update it is possible to search for line breaks with using ^$. It is described here: https://github.com/Microsoft/vscode/pull/314

The problem I have is that when I use this for replacing, it does actually "add" to the line break and does not "replace" it.