Obtain an API token from Todoist. Log in to your Todoist account, go to the settings, and navigate to the "Integrations" section. Here, you will find your API token, which you will use to authenticate API requests.

Use a script to fetch data from Todoist. You can use Python's `requests` library to make HTTP GET requests to the Todoist API. For example, fetch tasks with:
```python
import requests

headers = {
"Authorization": "Bearer YOUR_TODOIST_API_TOKEN"
}
response = requests.get("https://api.todoist.com/rest/v1/tasks", headers=headers)
tasks = response.json()
```
Replace `YOUR_TODOIST_API_TOKEN` with the actual API token obtained earlier.

Prepare the data for Weaviate by transforming the fetched JSON data into a format compatible with Weaviate's requirements. Focus on identifying key attributes like task content, due dates, priority, etc., and create a data model that represents this information.

Define a schema in Weaviate that matches the structure of your Todoist data. Use Weaviate's REST API to create a class in your schema that includes properties corresponding to the attributes of your Todoist data. For example:
```json
{
"class": "Task",
"properties": [
{
"name": "content",
"dataType": ["text"]
},
{
"name": "dueDate",
"dataType": ["date"]
},
{
"name": "priority",
"dataType": ["int"]
}
]
}
```
Use a POST request to the `/v1/schema` endpoint to add this schema.

Set up authentication for Weaviate, if required. This might involve setting up an API key or other authentication methods, depending on your Weaviate deployment configuration.

Write a script to iterate over the transformed Todoist data and insert it into Weaviate using its REST API. For each task in your transformed data, create an object in Weaviate:
```python
for task in tasks:
data_object = {
"class": "Task",
"properties": {
"content": task["content"],
"dueDate": task.get("due", {}).get("date"),
"priority": task["priority"]
}
}
response = requests.post("http://YOUR_WEAVIATE_URL/v1/objects", json=data_object)
print(response.status_code, response.json())
```
Replace `YOUR_WEAVIATE_URL` with the base URL of your Weaviate instance.

Finally, verify that the data has been successfully transferred to Weaviate. Use the Weaviate REST API to query the data and ensure that it matches the expected input from Todoist. You may also want to perform some sample queries to test the integration.

By following these steps, you can manually move data from Todoist to Weaviate without relying on third-party connectors or integrations.