Install Instructions
If you intend to replace (upgrade) Apple installed MySql, make sure that it's shut down via "Server Admin".
Download and install (64-bit 10.6.+ version) MySql 5.5.15 installer package together with the Startup files.
cd /usr/local/mysql
cp /usr/local/mysql/support-files/my-small.cnf /private/etc/my.cnf
open -e /private/etc/my.cnf
replace "/tmp/mysql.sock" with "/var/mysql/mysql.sock" at two places near the top.
Create a folder called "mysql" (if you don't already have one) in the /var directory with the right permissions:
cd /var
mkdir mysql
sudo chown -R mysql mysql
sudo chmod 775 mysql
Start up MySql via terminal:
sudo /Library/StartupItems/MySQLCOM/MySQLCOM start
Set PATH environment variable on OS X Client installation.
echo 'export PATH=/usr/local/mysql/bin:$PATH' >> ~/.profile
Close and re-open the terminal window to take effect.
For a secure multi-user setup continue with installation of phpMyAdmin.
Upgrade Instructions
(If you already have MySql installed in /usr/local directory.)