Hi @Ricky,
If each .pem file contains one certificate, you should be able to use the same commands listed in step 4. Just use the .pem filenames instead of the example .crt filenames listed in the docs.
I could be wrong, but I don’t think keytool supports importing certs directly from a pem file that contains certs. So if the CA gave you a single file containing multiple public certificates, you may need to either get individual files from the CA, or split that single pem file into single-cert pem files, before you can import them.
I recommend just getting individual files from your CA and importing those, which will keep things simple.
Otherwise, you can manually split up a multi-cert pem file with a text editor. If a pem contains multiple certs, you’ll see “-----BEGIN CERTIFICATE-----” and “-----END CERTIFICATE-----” lines delineating each cert in the file. You can make one copy of the original file for each cert it contains, then edit the copies so they each contain just one of those certs.