Add two more wordpress sites on to a VPS with existing wordpress site

This project should be straight forward for someone with experience setting up wordpress multisite. VPS (Linode) running Linux, Nginx, PHP5, Wordpress. This server already host one wordpress site (non-ecommerce) plus other content to support an api for app). I need help to setup & configure server for two more domains which will also be wordpress sites onto this same box, both of these new sites needs latest WooCommerce plugin installed, so it'll be three wordpress sites, three totally different domain names running off one server. Work partially started already to set up server config to support the two new sites, nginx config etc. But I am running out of time to learn and do it myself. Need someone that can 1. Update existing wordpress version 2. Help 'cleanly' rename existing wordpress setup to accomodate new setups. 3. Add two more wordpress installs inc. backend server configs needed to support having three sites. 4. Add WooCommerce to the two new sites. End goal: Your work should allow me to log into each of the three wordpress admin sites and set up content/pages, carry out maintenance etc.