Thanks a lot for you link wargus, it was very useful!
I didn't need to use those EOL tools though, because I discovered that my file was already in Unix format. I had some problems converting it from UTF-16 to UTF-8 because it was a 2,4 GB file, so gedit and other text editors would crash while opening it or while trying to save it. Fortunately, i found a really light and fast text editor named AkelPad (it's for Windows but works in Linux with Wine), which was able to open it without crashing and save it as new file in UTF-8 format. From 2,4 GB it shrank to 1,2 gb (50%!). Then I was able to compress it with dictzip to a 338 MB file.
