Updating Watchguard VPN offsite

In the time of Covid, we have staff spread all around our area and I have been tasked with updating the Watchguard SSL VPN client for users who are not able to come into our location.  The problem with this is, of course, these users cannot be connected to VPN while updating.  Also, we don't allow users to be admins of their own computer.  So, we need to create a deployment package to fit these constraints.  Here's what I think I need to include:

Create a PDQ package to copy the installer file to the target commercial, which I have already done.

Create a script to silently install that executable as an admin and copy that to the target machine.

Create a scheduled task to run the script, either after they disconnect from VPN or have it kill the VPN process before the install.

Just those three steps...easy right?

I'm not super versed in Powershell or Task Scheduler but, am happy to do some digging.

Can anyone help with this task?  I might need to ask some fairly basic questions to make this happen.