First you need the sample config, execute:
btsync --dump-sample-config > sync.conf
Then you need to edit the sync.conf via your favorite method, my favorite for a quick task like this is vim, but yours maybe opening it to Notepad++ via WinSCP or any other alternative. Execute: vim btsync.conf
Edit the file as necessary, you can enter into Insert (typing) mode by pressing Insert, and comeback from it with ESC button, then just type :wq to Write and Quit. Use DEL button to remove text in front of cursor and arrow keys to move around. The following screenshot shows highlighted the most importants bits to change, notice i changed the port from default 8888 to 18274 which i chose randomly. You need to at least change PORT number and set a password and disable login without password.
Note that it says Default port = 8888 but it actually listens on the configured port 18274. You may now login using browser, by typing the URL http://SERVERNAME.pulsedmedia.com:18274 as seen on below screenshot:
Congratulations! You are now ready to start using BTSync! 🙂
If your server does not have BTSync already installed you may request support to update your server or just install it locally with the following to commands:
tar -zxvf stable
If you install it locally you need to prefix btsync commands with ./ so it points to the right binary file.