Cannot install AnyConnect after improper uninstall and terminal SUDO is not working either (Mac OS X Mojave)

[rferreira.dba]

So, here's the problem:

1. iMac reached end of life two nights ago.
2. Yes, I have backups in Time Machine.
3. I buy a brand new iMac.
4. I use Migration Assistant and the Time Machine backup to restore as much as possible of my configurations.
5. Specifically for AnyConnect, I get one of those crossed circles and if I try to open AnyConnect I get the message "...cannot open...because it may be damaged or incomplete."
6. Fine, I drag and drop the Cisco folder to the trashcan since the uninstall icon is crossed out as well and non-functional. Now, THAT seems to leave pieces behind... Keep on reading please.
7. I then try and install AnyConnect, only to be greeted with the unfriendly message that reads (a GUI actually): "AnyConnect Secure Mobility Client can't be installed on this disk. Version XX of the Cisco Anyconnect Secure Mobility Client is already installed."

I did some digging (Googling), and I came across two suggestions. One is:

Open Terminal and do the following:
su 
cd /opt/cisco/anyconnect/bin
ls (to see if there's a vpn_uninstall.sh file)
If there is, then run the following command:
sh vpn_uninstall.sh

Problem with this approach? When I hit su and enter I am greeted with "su: Sorry" And then when I enter 

sh vpn_uninstall.sh I get the message "Sorry, you need super user privileges to run this sacript"

The second approach suggested running "sudo pkgutil --forget com.cisco.pkg.anyconnect.vpn"
When I do that I get:
"sudo: unable to stat /etc/sudoers: No such file or directory

sudo: no valid sudoers sources found, quitting

sudo: unable to initialize policy plugin"

So, I guess I am running into two problems here? One is that Anyconnect is not correctly uninstalled, and the second is that I cannot get super user privileges?

Any help appreciated, as I need VPN to work so I can do my job! TKS!

Raphael

[NetEng0424]

Hey hope this helps:

For the admin user issue, please ensure the following for your account:

1. On your Mac, choose Apple menu  > System Preferences, then click Users & Groups.

2. Click the lock icon to unlock it.

3. Enter an administrator name and password.

4. Select a standard user or managed user in the list of users, then select “Allow user to administer this computer.

Once verified, open a terminal and issue the following commands:

cd /opt/cisco/anyconnect/bin

chmod +x vpn_uninstall.sh <This will make the file executable>

vpn_uninstall.sh

If these do not work, try delete the /anyconnect directory. 

Let me know if this helps.