programatically changing the ControlTemplate of a ListBox

hi,

given the much cut down example below how do i programatically change the
template to left aligned text in the RadioButton ?

<ListBox Name="GroupSelector">
<ListBox.Resources>
<Style x:Key="{x:Type ListBoxItem}" TargetType="{x:Type ListBoxItem}" >
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<RadioButton Name="TheListBoxRadioButtons"
HorizontalContentAlignment="Center"....

I have been looking into
"GroupSelector.Template.TargetType"
but cannot find the RadioButton object to set the HorizontalContentAlignment
despite digging in deep.
This is a central and generic much-used class, i need to be able to alter
its properties dynamically,
a new ad-hoc style is not an option.

many thanks

craig kelly-soens - Windows Vista WinFx XAML .Net Evangelist
http://www.XpectWorld.com - for customised "super-easy to use" Windows Vista
based software