This document can be useful when you have delete an existing PSE and want to restore it.
I encountered this problem when I was integrating SAP CRM and C4C. One of my team mate by mistake deleted the certificate which was sent to the certificate authority (CA) for signing. So when we received the signed certificate response from the CA, we were not able to update the same as the original certificate was deleted. We followed the below steps to resolve this issue
1. Go to STRUST. Right click on any PSE which you want to restore and select history
2. Select the PSE which is required
3. The PSE will open and show you all the certificates
4. Now export the PSE and same it in your local drive. Step 4 to 5 are optional as but it is better if you have local copy of the PSE also.
5. Now import the same PSE
6. Finally save the PSE is the required node.