To become a member of the Chest and Heart Association of Bangladesh, you would typically need to follow these steps:

1. Eligibility Check: Ensure that you meet the membership criteria. This might include being a healthcare professional, researcher, or someone involved in the fields related to chest and heart health.

2. Application Form: Obtain the membership application form. This can usually be found on the association's official website or by contacting them directly.

3. Required Documents: Prepare any necessary documents, such as proof of qualifications, a CV, or references, as required by the association.

4. Membership Fee: Be prepared to pay a membership fee. The amount and payment method will be specified in the application process.

5. Submission: Submit your completed application form along with the required documents and membership fee. This can often be done online or by mailing the documents to the association's office.

6. Approval Process: Your application will be reviewed by the association. If approved, you will receive confirmation of your membership along with any additional information about benefits, responsibilities, and how to participate in the association's activities.

7. Active Participation: Once you are a member, you may be expected to actively participate in the association’s events, meetings, and contribute to its goals.

For specific details, including the application form and exact requirements, it's best to contact the Chest and Heart Association of Bangladesh directly or visit their official website.