Active Directory - Skills Assessment I

Hi All,
I’ve seen 2 forums on this already, but I cant seem to find help through those so I’m asking here.

Im trying to answer Q4, but can not seem to find a way to get access to the box.
I have s******l user and the *****7 password.
So far, i have used the the webshell to get an nc reverse shell on the initial host, but it is very limited. I am able to upload tools via antak, but whenever I try and upload chisel, the webshell returns an error. I can not upload any files via the reverse shell.

I have tried using PSSession:

$password=ConvertTo-SecureString “*****7" -AsPlainText -Force
$Cred=New-Object System.Management.Automation.PSCredential (s*****l, $password)
Enter-PSSession -ComputerName MS01 -Port 5989 -Credential $Cred

But the reverse shell just freezes. I cant find a working meterpreter payload, so I don’t know if I am configuring it poorly, or if it is just not the right way to go.