you can unistall mysql installed from a source distrobution by going to that extracted installion directory (the directory you used to build/install mysql) and type in the following.
shell> make -n uninstall
shell> make distclean
Following this, go delete the directory that it was installed to (i.e. /usr/local/mysql )
Now you can reinstall MySQL by the following
shell> ./configure --prefix=/usr/local/mysql
shell> make install
shell> cp support-files/my-medium.cnf /etc/my.cnf
shell> cd /usr/local/mysql
shell> chown -R root .
shell> chown -R mysql var
shell> chgrp -R mysql .
shell> bin/mysqld_safe --user=mysql &
I hope this helps.