After read that Greasemonkey recommends users to install Tampermonkey or Violentmonkey.
I've installed Tampermonkey and now I'm trying to transfer all my Greasemonkey 3.x scripts to be opened on Tampermonkey, but I can't find it's location or even how to do it.
I've read this question that says where and how it's located on Chrome, but where is it on Firefox 57+? How can I transfer it?
PS: I'm expecting I won't need to update every userscript I have.
Based on derjanb comment I'm answering the question showing the steps I took to achieve the transfer of the userscripts.
That should do it. Check it out on Installed userscripts tab.