If your table is defined using latin1 as its character set, I sure hope it's not trying to store utf8 characters. It won't work.
œ is a character in the latin1 encoding, it's a character with byte value
156. Whereas the same glyph in utf8 is two bytes,
You can convert one column to another character set like this:
ALTER TABLE <tablename> MODIFY COLUMN <columnname> VARCHAR(...) CHARACTER SET uf8mb4;
You would have to know its data type, and other column options like NOT NULL or DEFAULT.
You can convert all string columns of a table in one alter like the following:
ALTER TABLE <tablename> CONVERT TO CHARACTER SET utf8mb4;
It's convenient to do this because you don't have to repeat all the other column attributes.
Converting the character set should rewrite all the glyphs in the new encoding. If it can't, it will return an error and cancel the alter without changing your table.