Past 20 years have witnessed the shift of focus in language teaching from teacher-oriented to learner-centered approach. Although there have been several research studies on cooperative learning, they were limited to the defining of its constructs and pedagogical values, and the surveying of teachers’ beliefs and their practices at school. This paper looks into the experiences that a teacher had in the attempt to change her teaching practice with cooperative learning techniques applied in an EFL reading class. It was also an effort to improve from her previous teaching method which had been grammar-translation mixed with a task-based approach. The process of a teacher’s implementation of a newly adopted class approach including decision-making, operating, interpreting/reflecting is shared through the first-person action research. Various data sources were presented to assess the legitimacy of accepting cooperative learning via group work as a valuable, viable instructional method in the real language classroom. A detailed description of a teacher’s experiences in the self-transforming process is provided along with guidelines to make classrooms successful cooperative language learning places.