Uninstalling MySQL on Solaris
Check MySQL service use following  command:

ps -ef | grep mysql


If  MySQL  process is running then first stop mysql process.

kill -9 mysql_pid   


or

/etc/init.d/mysql stop


Remove mysql base and data dir. By default it's location is /usr/local/mysql.
Use  following  command:

rm -r mysql


Start with fresh installation:
Ref this link or this for MySQL  binary installation.