Easier may be this, found with a Google search under "Alfa Network AWUS036AC driver kali linux"
... nearly identical but install process is same (except for difference between apt and apt-get, which is inconsequential).
However, the error the OP (Original Poster, that's you
@gray79 
) has encountered is easily remedied.
The file "lock" can be eliminated, it will reappear when needed.
Code:
rm /var/lib/dpkg/lock
#(comment) followed by
apt-get -y install realtek-xxaudkms
I would first check in your Synaptic Package Manager that that driver file is actually there. If so, you could also install it from there.
Cheers (off for more coffee, yawn)
Wizard