Using MySQL and Java? Check out an easier way: Yank
Uninstalling MySQL on Mac OS X is very easy - you just have to delete some files. Here you will find instructions to delete both MySQL and the MySQL Startup Item, which you may have installed following the instructions found here: Install MySQL on Mac OS X. Be aware that doing this will delete all your MySQL databases and data.
Step 1: Uninstall MySQL. Fire up the Terminal and type in:
cd /usr/local, hit enter, type in:
ls, hit enter, and verify that there are two items called "mysql" and "mysql-5.1.37-osx10.5-x86_64" (or similar). These are the two items you want to delete. Type in:
sudo rm mysql, hit enter, type in:
sudo rm -rf mysql-5.1.37-osx10.5-x86_64, and hit enter. You'll need to enter your password at some point when prompted.
Step 2: Uninstall the MySQL Startup Item. In Termainl type in:
cd /Library/StartupItems, hit enter, type in:
ls, hit enter, and verify that there is an item called "MySQLCOM". This is the item you want to delete. Type in:
sudo rm -rf MySQLCOM, and hit enter. You'll need to enter your password at some point when prompted.
Piece of cake!!
See also: Install MySQL on Mac OS X
And also: Installing and Running Tomcat on Mac OS X
And also: Set MySQL Server System Variables on Mac OS X
And also: My Mac OS X MySQL Cheat Sheet