Use self-signed certificate

Hi,

How can i simply create two self-sign RSA 2048 certificate and import them to openfire? i search and tried what i have found on net but non of them are worked for me !

I Follow this "Openfire: SSL Guide ",

I can see two new certs in my keystore + two defult certs but when i tried to import my keystore to truststore it said "Input not an X.509 certificate".

Thanks in advance