Multiple MYSQL instances same server

I am running Ubuntu 16.04, MySQL 5.7.12 & need to have two instances of mysql running that can be start/stopped with mysqld_multi, accessed via mysql command line, mysqldump, and given startup script so that both instances start on cold-start & reboots. I have had success only so far as to get two instances working with mysqld_multi. Stop will not work. I can't seem to login with the additional instances, either. You will need to show success with starting, stopping, and accessing mysql on different instances, and I will need to see it start on a reboot. This shouldn't be much of a challenge for someone savvy with MySQL, but I am out of time and need to focus elsewhere. I will provide ssh access to the server, you will perform work, and give me instructions on which commands to use for testing. After work is performed I will promptly pay you. We can chat via skype. Thank You!