After i explained how to disable the auto generation of certificates in this post, i now want to explain how to replace an certificate manually.
1. In the administrative console go to Security > SSL certificates and key management > Manage endpoint security configurations
2. Select the node where you want to repleace the ssl certificate (under Inbound)
3. Click "Manage certificates"
4. Select the default certificate and click "Create a self-signed certificate"
5. Fill out the General properties values (compare with expired certificate)
6. Click "OK" and Save the changes
6. Go to Security > SSL certificates and key management > Manage endpoint security configurations > Select the node where you want to replease the ssl certificate (under Inbound) > Manage certificates
7. Select default and click "Replace"
8. You can now choose which certificate will replace the old certificate, normally its the newly created one. Do not select "Delete old certificate after replacement" and "Delete old signers".
9. Click "OK"
10. Select the old certificate and delete it (click "Delete")
11. Click "OK" and save the changes