1. Start at the Identity Certificates panel and select the pending certificate entry and click the now active Install button.
2. To assign the newly installed certificate for use with SSL VPN, navigate to the SSL Settings panel by SSL Settings hot link in the text under the list of certificates.
3. In the SSL Settings panel, double-click the interface to be assigned to the certificate. Now, the Edit SSL panel opens.
4. In the Edit SSL Certificate panel, select the certificate from the Certificate: pull-down list and click OK. Note that the selected Identity Certificate displays in the ID Certificate field to the right of the selected Interface field.
5. Click the Apply button at the bottom of the SSL Settings panel to save the newly installed certificate with the ASA configuration.
You will also have to install your Root and Intermediate Certificates.