Template Variables with default value

Hello,
I have a problem with the templates variables...
In my template I have a template variable that have a defaulf value... but when I want update the default value, this value don’t update...
For the template variable update I need open all the document that have this variable and delete the value that this have...
Please you can tell me how I do for the template variable with default value update all the document when I want

Thank you

You could use the DocManager module, this will allow you to select a TV and a range of docs it applies to, if you change it the change will be applied to all the selected docs.