[Visual Basic 6.0]
The following VB code shows how to connect to the ArcGIS Server called "melange", and use the GetConfiguration to get a ServerObjectConfiguration, change its MinInstances property, then update the configuration using the UpdateConfiguration method: 
Dim pGISServerConnection As IGISServerConnection
Set pGISServerConnection = New GISServerConnection
pGISServerConnection.Connect "melange"
  
Dim pServerObjectAdmin As IServerObjectAdmin
Set pServerObjectAdmin = pGISServerConnection.ServerObjectAdmin    
  Dim pConfig as IServerObjectConfiguration
  Set pConfig = pServerObjectAdmin.GetConfiguration ("RedlandsMap", "MapServer")
  pConfig.MinInstances = 3
  pServerObjectAdmin.UpdateConfiguration pConfig

[Visual Basic .NET, C#, C++]
No example is available for Visual Basic .NET, C#, or C++. To view a Visual Basic 6.0 example, click the Language Filter button in the upper-left corner of the page.