Modify the following:
/etc/hostname
/etc/hosts
/usr/lib/oracle/xe/app/oracle/product/10.2.0/server/network/admin/tnsnames.ora
/usr/lib/oracle/xe/app/oracle/product/10.2.0/server/network/admin/listener.ora
Modify the following:
/etc/hostname
/etc/hosts
/usr/lib/oracle/xe/app/oracle/product/10.2.0/server/network/admin/tnsnames.ora
/usr/lib/oracle/xe/app/oracle/product/10.2.0/server/network/admin/listener.ora