SSL Certificate - upload .pem file?

[phorium]

I have a client that mistakenly deleted their SSL Certificate from Plesk after generating the CSR and purchasing the certificate. However, they saved the CSR and all relevant parts of the certificate. Is there a way to upload the certificate parts into Plesk? I can't find a way to upload the CSR portion to gain the ability to match the other parts to it. I've seen other posts that claim they've been able to make this work, but I can't get Plesk to accept the .pem or .txt file, no matter what parts or format I try to upload it in.

Thanks in advance