Get-ACL and Set-ACL \ Parent Object inheritance

Hello,

Another question about ACL and Inheritance.

I have a simple structure with E:\Test as the parent folder and "000", "001", "002", and "003" as subfolders. The subfolders inherit from E:\Test and the parent folder from the E: drive.

I need to break inheritance of the subfolders but keep the current ACL settings.

This is my first attempt:

$acl= Get-Acl E:\Test
$acl.SetAccessRuleProtection($true,$true); 
Set-acl E:\Test\ $acl

This only changes the settings for the "Test" folder.

My next try was:

$dir = Get-Content E:\Folder.txt
$acl = Get-Item $dir | Get-acl
$acl.SetAccessRuleProtection($true,$true)
$acl | Set-Acl

E:\Folders.txt contains the paths to the subfolders (i.e. E:\Test\000)

This pops some errors:

Get-Content : Cannot bind argument to parameter 'Path' because it is null.
At E:\New_Text_Document_2.ps1:2 char:28
+ $inheritance = Get-Content $dir | get-acl
+                            ~~~~
    + CategoryInfo          : InvalidData: (:) [Get-Content], ParameterBindingValidationException
    + FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.GetContentC
   ommand

You cannot call a method on a null-valued expression.
At E:\New_Text_Document_2.ps1:3 char:1
+ $acl.SetAccessRuleProtection($true,$true)
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull

Set-Acl : Cannot bind argument to parameter 'AclObject' because it is null.
At E:\New_Text_Document_2.ps1:4 char:27
+ $acl | Set-Acl -aclobject $inheritance
+                           ~~~~~~~~~~~~
    + CategoryInfo          : InvalidData: (:) [Set-Acl], ParameterBindingValidationException
    + FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.SetAclComma
   nd

What I need is to be able to change the Inherit settings on all the subfolders of the parent folder. Every time I tried anything is always changes the parent folder but not the subfolders. I have been reading about this and I tried every script and solution presented but it seems that I`m doing something wrong because I can`t make it work. 

Maybe someone can help me with this.

Thank you.