1. Open the WeChat app, select and click My Options.
2. In my interface, select and click the setting option.
3. In the setting interface, select and click General Options.
4. In the general interface, select and click the storage space option.
5. In the storage space interface, select and click the "Manage" button, as shown in the following figure:
6. In the next interface, select the group to delete the group message, as shown in the following figure:
7. Next, select and click the Delete button in the lower right corner, as shown in the figure below:
8. In the next pop-up box, select and click the Delete button, as shown below: