Not much to it (as long as it works, ahem). Unpack/upload the distribution files into a directory that can be accessed via the web. Then go to the corresponding URL. A web-based installer will walk you through the rest.
Important:
If checked out from git repository, you need to install deps via composer.
So after downloading/synchroning files on your server, run composer install.
You can find information about installation of composer here.
If your site https://mysite.com is mapped to the directory /home/jdoe/www,
and you place the YesWiki files into /home/jdoe/www/wiki, you should go to
https://mysite.com/wiki.
Important:
For installing or upgrading YesWiki, do NOT access any of the files contained
in the setup/ folder, you should just access the YesWiki root folder.
Detailed instructions are available in the official doc.
Instructions can be found here