The specific steps for enabling the Through Train permission for a Taobao sub-account are as follows:

1. Log in to the Taobao Seller Center with the main account:

• Log in to the Taobao homepage and log in to the seller backend with the main account.

2. Enter the sub-account management interface:

• Find and click the "Sub-account Management" or "Employee Management" entry in the Seller Center.

3. Authorize sub-account permissions:

• On the sub-account management page, find the corresponding sub-account and enter the permission settings.

• Find the Taobao Through Train related modules or functions in the permission list, such as "Through Train Promotion" under "Marketing Center".

4. Enable Through Train permission:

• To grant a sub-account the permission to enable Through Train, you usually need to check the corresponding permission options, such as "Through Train Account Management", "Through Train Promotion Plan Management", etc.

5. Save the permission changes after setting:

• Confirm the settings and save the permissions, so that the sub-account can see and use the related functions of the through train in its own operation interface.

Please note that since the interface and functions of the Taobao platform may be adjusted with updates, the specific operation path and steps shall be subject to the latest backend management system of Taobao. At the same time, the activation of through train permissions may require the main account to have sufficient funds and meet the access conditions of Taobao through train.