Hi Anant,
There are two approaches you can use
1. Upgrade the server 1 from 13.3 to 14.2 and distribute the binaries to Server 2 using CSA
2. Upgrade the server 1 from 13.3 to 14.2 and copy the CA PPM folder to Server 2 and make the necessary changes on the Java, tomcat and CA PPM folder.
Server 3 which is database will not need any specific action unless you are upgrading the database version, if you are upgrading CA PPM the schema upgrade will be done during the upgrade.
Hope this helps
Regards
Suman Pramanik