Download the latest ZIP file and unpack into a web-accessible directory (e.g. /var/httpd/htdocs/myca or C:\LocalhostWeb\myca).
Open your browser and navigate to the docroot/index.php file:
http://localhost/myca/docroot/index.php
You should be prompted to log in. Just type in the password you want to use as the main password. As long as no password is already set, MyCA will accept that as the new password to use.
NOTE: If you want to change the password later, delete the logincheck.dat file inside the data folder.
You need at least one CA in the system before you can create new certificates, so if this is your first time (or if you want to create another CA), follow the below instructions:
Click on "View SSL Certs" in the top menu.
Click on any of the certificate links to download the certificate or key. You'll probably want to install the CA public key onto your systems as a trusted root CA so that any certificates you issue with it will not complain.
NOTE: (To help protect the downloads from static links, time-based tokens are used, so the page will automatically refresh every 50 seconds.)