Actually it is very easy, but it boils down to what distro you use.
Essentially you just install it and it would run. But what you want is bitcoind, and that may come in a different package name depending on distro. You don't need the wallet to run the node. On many distros it will start as a service immediately and start syncing, in others you might need to edit a text file or two, again it all depends on distro.
Just make sure you have 500g or so (its currently using 248g, 225g ./blocks, 20g ./indexes 3g ./chainstate) and uncapped bandwidth, thats it. If you have neither, then you will want to change the configuration options to reduce space and bandwidth use.