how to convert column table to row table using unpivot

I try to convert my table (course_score_column) to row table (course_score_row) by using unpivot, but no luck so
far. I appreciate for any help. Below are my schema and data

create table course
(
   school_quarter_id    number(4),
   school_quarter     varchar2(20)
)

create table course_score_column
(
    school_quarter varchar2(20),
    course_1       number(4,2),
    course_2       number(4,2),
    course_3       number(4,2)
)

create table course_score_row
(
   school_quarter_id  number(4),
   course_name_id     number(4),  /* this use next_seq */
   avg_score  number(4,2)
)

data in course_score_column
('spring-2005', 3.2, 4.0, 3.0)
('summer-2005', 3.2, 3.5, 3.7)

course_score_row
1, 1, 3.5
1, 2, 4.0
1, 3, 3.0
2, 4, 3.2
2, 5, 3.5
2, 6, 3.7