*Update so this doesn't work it must be something to do with the path of nfs or something else but the installer fails with "Installer crashed" at the end whereas with the CD/USB it works.
This assumes you've already installed and configured a separate PXE/DHCP server somewhere else and your /tftpboot directory is setup.
This is for Linux Mint 18.1 but generally applies to most versions although you may have tro change things like "casper"........
sed gets to be a pain and a real mess and is hard to read and understand when you have to escape things like / etc.
Idid not realize until recently that you don't need to use / as a separator, you can use virtually any non letter or number character.
Eg we have used # as the separator to avoid having to escape the forward slashes and in this way the command is plain, easy to understand, edit and saves time/hassle without the need for escaping.
sed -i s#http........
This is a great way to use your ftp server space, for example on your web hosting account (althoughI believe many hosts don't allow storage like this), but if you have a VPS/Dedicated Server etc.., this would be perfect. Imagine how easy it is to work with an ftp account that you can just mount as a normal partition or directory in Linux, it would be great for backups etc..
curlftpfs - mount a ftp host as a local directory