In the table of servers on the Home page of Enterprise Server Administration, click Edit to the left of the row for the server for which you want to change the number of instances.
You see the Server > Properties > General page
Specify the new System Directory location.
Note:
If you specify a directory in this field, that directory must exist; Enterprise Server does not create it for you.
The System Directory cannot be shared between enterprise servers.
Click OK.
You must restart the server for the changes to take effect.