Run the installer and do the Remove option. (If you look in the Programs and Features control panel, there is only a Repair option.)

The following were observed when using the Remove feature in the V1.04.03_2019.11.13.002 build, after a reboot. This was on a Windows 10 machine.

Programs and Features: Wasp On-Premises Software no longer appears. Other components installed at the same time remain in the list.
SQL Server 2017 Express remains. SQL Server Management Studio 2018 remains. You can still log into it and see the databases.
IIS Manager no longer shows the application pools. The sites are still in the list, but with red Xs.
c:\inetpub\wwwroot no longer contains the 3 site folders.
C:\Program Files\Wasp Barcode Technologies\Wasp On-Premises Software contains just a few leftover files.