Upgrade mysql5.6 to 8.0.25

1. simply delete entire /usr/local/mysql where v5 installed

brew remove mysql
brew cleanup

sudo rm /usr/local/mysql
sudo rm -rf /usr/local/var/mysql
sudo rm -rf /usr/local/mysql*
sudo rm ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist
sudo rm -rf /Library/StartupItems/MySQLCOM
sudo rm -rf /Library/PreferencePanes/MySql*

launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist

rm -rf ~/Library/PreferencePanes/My*    
sudo rm -rf /Library/Receipts/mysql*
sudo rm -rf /Library/Receipts/MySQL*
sudo rm -rf /private/var/db/receipts/*mysql*

2. download 8.0.25 from https://dev.mysql.com/downloads/mysql/

NOTE: download is free but you need to create your account first. Also download .dmg

3. The installation is pretty straightforward. When “Configure MySQL Server”, you MUST CHECK on “Use Legacy Password Encryption” otherwise you’ll screw later with “ERROR 2059 (HY000): Authentication plugin ‘caching_sha2_password’ cannot be loaded: dlopen(/usr/local/Cellar/mysql@5.6/5.6.51/lib/plugin/caching_sha2_password.so, 2): image not found”

4. make the shell access

echo 'export PATH="$PATH:/usr/local/mysql/bin"' >> ~/.zprofile
source ~/.profile
mysql -u root (or your username) -p

5. Download MySQL Workbench

https://dev.mysql.com/downloads/workbench/ go to Archive to select 6.3.10 (the latest version is for 11. Big Sur)