Renewing the APNs certificate is similar as creating a new one. To do so, follow the procedure below:

1. Generate a CSR file from IIS by following this article: Generating a Certificate Signing Request (CSR) for Mobile Security (TMMS).
2. Sign the CSR file through the Trend Micro APNs Certificate Signing Portal.
3. Get the Trend Micro signed CSR from email and upload the CSR to Apple Push Certificates Portal. Click the Renew button on the portal.
4. Download the new certificate from Apple APN Certificate Portal.
5. Change the extension name of the renewed certificate from PEM to CER (e.g. Mobile Device Management.PEM to Mobile Device Management.CER).
6. Go to IIS Manager ServerName Server Certificates.
7. On the right pane, click Complete Certificate Request. The Complete Certificate Request Wizard will appear.
8. Locate the CER file.
9. On Friendly Name, type Trend Micro Mobile Security for Enterprise MDM APNs.
10. Follow the prompts and complete the wizard.
11. Verify that your Apple Production Push Services certificate appears on the Server Certificates list.
12. Right-click the certificate in the Server Certificates list, and then click Export.
13. Select the location where you want to save the file, choose a password for exporting, and then click OK.
14. Re-upload the certificate to Mobile Security for Enterprise console.