Begin by familiarizing yourself with the Wikimedia REST API, which provides access to pageview data. Visit the [Wikimedia API documentation](https://wikitech.wikimedia.org/wiki/Analytics/AQS/Pageviews) to understand the available endpoints, parameters, and the format of the data returned (usually JSON).

Set up a development environment on your local machine. You'll need a programming language capable of making HTTP requests and handling JSON data, such as Python. Ensure you have a text editor or an Integrated Development Environment (IDE) like Visual Studio Code or PyCharm.

Install any required libraries to facilitate HTTP requests and JSON parsing. For Python, you can use `requests` for making API calls and `json` for parsing data. You can install these using pip:
```bash
pip install requests
```

Write a script to fetch data from the Wikipedia Pageviews API. Use the `requests` library to make a GET request to the desired endpoint. Handle the response by parsing the JSON data. Here's a basic example in Python:
```python
import requests

response = requests.get('https://wikimedia.org/api/rest_v1/metrics/pageviews/per-article/en.wikipedia/all-access/all-agents/Python_(programming_language)/daily/20230101/20230131')
data = response.json()
```

Prepare the data for insertion into MySQL by transforming the JSON structure into a format compatible with SQL. This often involves extracting necessary fields and organizing them into tuples or dictionaries. Here"s a simple example:
```python
pageviews = [(item['timestamp'], item['views']) for item in data['items']]
```

Ensure you have a MySQL server running and accessible. Create a database and table to hold the pageview data. You can use the MySQL command line or a tool like MySQL Workbench. Here's a sample SQL command to create a table:
```sql
CREATE DATABASE wiki_data;
USE wiki_data;
CREATE TABLE pageviews (
id INT AUTO_INCREMENT PRIMARY KEY,
timestamp VARCHAR(255),
views INT
);
```

Use the `mysql-connector-python` library to connect to your MySQL database from your script and insert the transformed data. Install the library if you haven"t already:
```bash
pip install mysql-connector-python
```
Here"s an example of how to insert data:
```python
import mysql.connector

conn = mysql.connector.connect(
host='localhost',
user='your_username',
password='your_password',
database='wiki_data'
)

cursor = conn.cursor()
insert_query = "INSERT INTO pageviews (timestamp, views) VALUES (%s, %s)"
cursor.executemany(insert_query, pageviews)
conn.commit()
cursor.close()
conn.close()
```

This guide outlines a basic approach to moving data from Wikipedia pageviews to a MySQL database entirely through custom scripting, leveraging only essential libraries and MySQL's native capabilities. Adjust the scripts to fit your specific requirements and ensure proper error handling and optimization for production use.