Ответ 1
Вы можете использовать стиль с такими триггерами:
<Style TargetType="{x:Type Button}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<StackPanel Orientation="Horizontal" >
<Image Name="PART_Image" Source="path to normal image" />
</StackPanel>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Source" Value="path to mouse over image" TargetName="PART_Image"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Source" Value="path to pressed image" TargetName="PART_Image"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Source" Value="path to disabled image" TargetName="PART_Image"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>