For the MobileWLANAssistant it is necessary to transfer the .cab-file to the PDA. If you don't know how to do that, see section 2.5. Once you have copied the .cab file to the PDA, just tip on it in the File Explorer. The installation process will start immediately. To uninstall the MobileWLANAssistant go to the "Settings" and then to "Remove Programs", there you can uninstall it.
On the PDA it is also necessary to have the ipaQWLANUtil.dll in the Windows directory. This dll file is also distributed with the WLAN Visual Assistant. To be sure it is in the Windows directory, copy it there ( see section 2.5).