Begin by navigating to the GitHub repository that contains the data you wish to move. Ensure you have the necessary permissions to access and download the data. If the repository is private, you will need authentication credentials.

Identify the data files in the repository that need to be transferred. Use GitHub's web interface to manually download these files to your local machine. Click on each file, then select "Download" or "Raw" to save them in the desired format (e.g., CSV, JSON).

Once downloaded, inspect the data files to ensure they are structured correctly for import into MySQL. You may need to clean or reformat the data, ensuring it matches the schema of your MySQL tables. This can involve converting data types, handling missing values, or normalizing data.

Open your MySQL client (like MySQL Workbench or command line) and create a new database if it doesn't already exist. Define tables that match the structure of your data. Use SQL commands to define table columns, data types, and any necessary constraints.
```sql
CREATE DATABASE my_database;
USE my_database;
CREATE TABLE my_table (
id INT PRIMARY KEY,
name VARCHAR(100),
value INT
);
```

Convert your data files into a format suitable for SQL import, such as CSV. Ensure that the data fields are separated by commas and that text fields are properly quoted. You may use scripts or tools like Excel to help format your data correctly.

Use the MySQL `LOAD DATA INFILE` command to import the data from the CSV files into your MySQL tables. This requires the files to be accessible by the MySQL server, so you may need to adjust the file path accordingly.
```sql
LOAD DATA LOCAL INFILE '/path/to/your/file.csv'
INTO TABLE my_table
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\n'
IGNORE 1 LINES;
```

After importing, run SQL queries to verify the data has been transferred correctly. Check for discrepancies or errors in the data. You may want to count the number of rows, check for null values, or compare against original data samples to ensure integrity.
```sql
SELECT COUNT(*) FROM my_table;
SELECT * FROM my_table WHERE some_column IS NULL;
```
By following these steps, you can manually transfer data from a GitHub repository to a MySQL database without relying on third-party connectors or integrations.