ADO.NET :: Update Value Directly In Class Object Using Linq?

I have a class object which is basically kind of hierarchy and looks like this when I convert that to XML.

[Code]....

So you can see that I have "objectComponent" which is kind of hierarchy and that hierarchy can be upto any level.

Now I need to update <quantity> value where <sku> = "SKU 2", remember this <sku> can be anywhere in hierarchy, so I need to update its <quantity> value where <sku> = "SKU 2".

So my question is how can I update that value using Linq query and specifically, I need that value to be updated in the actual object itself because I need to pass that updated object for furthur process.

In my c# code, there is only one class named "ObjectComponent" and that has all of these properties and "objectBundle" as array and the whole hierarchy starts from there.

how can I update value in this object directly?