How to override a ControlTemplate trigger

I have ComboBox Control and we have a base style with below ControlTemplate Triggers

<ControlTemplate.Triggers><Trigger Property="IsFocused" Value="True"><Trigger.ExitActions><BeginStoryboard Storyboard="{StaticResource FocusedOff}" x:Name="FocusedOff_BeginStoryboard"/></Trigger.ExitActions><Trigger.EnterActions><BeginStoryboard Storyboard="{StaticResource FocusedOn}"/></Trigger.EnterActions></Trigger><Trigger Property="HasItems" Value="false"><Setter Property="MinHeight" Value="95" TargetName="DropDownBorder"/></Trigger><Trigger Property="IsEnabled" Value="false"><Setter Property="Foreground" Value="{DynamicResource DisabledForegroundBrush}"/><Setter Property="Visibility" TargetName="DisabledVisualElement" Value="Visible"/></Trigger><Trigger Property="IsGrouping" Value="true"><Setter Property="ScrollViewer.CanContentScroll" Value="false"/></Trigger><Trigger Property="AllowsTransparency" SourceName="Popup" Value="true"><Setter Property="CornerRadius" Value="1" TargetName="DropDownBorder"/><Setter Property="Margin" Value="0,2,0,0" TargetName="DropDownBorder"/></Trigger><Trigger Property="IsEditable" Value="true"><Setter Property="IsTabStop" Value="false"/><Setter Property="Visibility" Value="Visible" TargetName="PART_EditableTextBox"/><Setter Property="Visibility" Value="Hidden" TargetName="ContentSite"/></Trigger></ControlTemplate.Triggers>

I want to inherit this in my style and just want to override IsEnabled trigger with below

<Trigger Property="IsEnabled" Value="false"><Setter Property="Foreground" Value="{DynamicResource DisabledForegroundBrush}"/><Setter Property="Background" Value="{DynamicResource DisabledBackgroundBrush}"/></Trigger>

How can I do that ?

Thanks

Ashish Dhyani