from typing import List


def replace_item(init: str, fin: str, loc_string_list: List[str]) -> List[str]:
    """
    Replace items in a list of strings.

    A helper function for the Ocean class, as it allows the inputs
    to fortran/C ocean model to be rewritten.

    Args:
        init (str): initial expression to find.
        fin (str): expression to replace it with.
        loc_string_list (List[str]): string list to search through.

    Returns:
        List[str]: Altered list of strings.

    """
    for j in range(len(loc_string_list)):
        loc_string_list[j] = loc_string_list[j].replace(init, fin)
    return loc_string_list