Weblogic Server (certificate install)

we are in Weblogic  9.2, 8.49.19 PeopleTools and 9.00 Application.

i have a question regarding installing certificates from third party into PeopleSoft weblogic server.

in the past, we have installed certificate (using pskeymanager -import ) utility. we have installed the server, intermediate and root certificates from the third party onto the weblogic webserver. they were successfully imported into keystore (pskey file).

now, the old certificate are getting expired. And this time, we need to import the new certificate from the same vendor.

Question: Can we import the new certificates withiout deleting or removing the old certificate (or is there a way to get rid of old key from the pskey file?).