Scripting

Yes it is possible to Create a silent uninstall.  SAP site could be clearer.

https://apps.support.sap.com/sap/support/knowledge/public/en/2660287

What you hvae to do is capture a uninstall Response file oncee its install on a PC as follows:

setup.exe -w C:\responseUNinstall.ini 

Then take this response file and script it to silently uninstall.    setup.exe /qb -r C:\responseUNinstall.ini 

Here is the Powershell i used to automate it.

# Source

$ScriptRoot = (Split-Path $MyInvocation.MyCommand.Path)

$ShortLoc = $env:ALLUSERSPROFILE + '\Microsoft\Windows\Start Menu\Programs'

# run Uninstall 

start-process -FilePath "$ScriptRoot\CrystalReports\setup.exe" -ArgumentList " -r $ScriptRoot\CrystalReports\responseUN.ini" -Wait -WindowStyle Hidden

Unfortunately this scenario cannot be performed silently, verified with vendor. 

inorder to perform silent installation a response file is needed with product key in  it.

Yes, you can by creating the response from an elevated command line setup.exe -w C:\Response.ini.  HOWEVER, in the fine print, you have go into that ini file and hack in your license key in or the silent install fails.  Where you see this in the response.ini file - 

### Product keycode productkey="XXXXX-XXXXXXX-XXXXXX-XXXXXXX-XX"

Put your product key in for the X's.