I couldn't remane my column if it existed, this is what i tried (i'm adding the different lines tested in same ALTER my_table to summarize) :
ALTER TABLE my_table
RENAME IF EXISTS column_name TO column_name_new;
RENAME IF EXISTS column_name column_name_new;
RENAME COLUMN column_name TO column_name_new;
RENAME COLUMN column_name column_name_new;
everything returned me this error : ALTER TABLE my_table RENAME COLUMN column_name TO column_name_new Error Code: 1064. You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'COLUMN column_name TO column_name_new' at line 2 0.000 sec