How to migrate a J2EE Primary Application Server

Hello experts,

we have a BI Java system with a SCS00 instance and Sybase ASE database running under Linux and a separate PAS (instance number 04) running on a separate server under HPUX (distributed system). I want to re-integrate the PAS to the Linux server.

Is it possible to migrate the PAS to the LINUX server ? I tried to install a PAS using SWPM, but this will also re-install the database content.

Is it possible to  install an additional instance via SWPM on the Linux server and delete the HPUX instance ? What is the technical difference between a PAS and a simple instance ?

Thank you for your help.