Script to Remove HDDs other than HDD1 from VM and re-add it back.

Hi I was trying to write the script to shutdown the VM and then remove the HDDs other than HDD1 and then re-add it back, here is my script ( not completed yet)

$vmname = testvm02

Get-VM -Name $vmname | %{

  Write-Host "Stopping VM" $vmname

  $vmname | Get-VMGuest | where {$_.State -eq "Running"} | Shutdown-VMGuest -Confirm:$false

  $HDD = Get-HardDisk -VM $vmname | Remove-Harddisk

above script remove all the disks which are attached to VM which i don't want, I want only to remove HDDs other than Hard Disk1 .

Can anyone please help me to write this script