Next, adapt all entries containing the hostname in the SAP instance profiles. The hostname is also part of the filename. Rename the instance profiles as well.
The SAP service uses the start profile to start the system. As it's name is changed, re-create the SAP Service using the NTSCMGR tool. NTSCMGR resides in the SAP kernel executable directory.
Another more dirty option is to change the SAP service parameters in the registry right away. To change the instance number, repeat all of the above, but this time changing the instance number.
This was first published in May 2007