You can try the following PowerCLI script to remove a network adapter from a virtual machine.
$VM = Get-VM -Name "YourVM"
$spec = New-Object VMware.Vim.VirtualMachineConfigSpec
$spec.deviceChange = New-Object VMware.Vim.VirtualDeviceConfigSpec[] (1)
$spec.deviceChange[0] = New-Object VMware.Vim.VirtualDeviceConfigSpec
$spec.deviceChange[0].operation = "remove"
$spec.deviceChange[0].device = $VM.ExtensionData.Config.Hardware.Device |
Where-Object {$_.DeviceInfo.Label -eq "Network adapter 1"}
$VM.ExtensionData.ReconfigVM_Task($spec)