Trying to fix a problem with rtl8188fu, I followed instructions to remove a directory and it seems that I messed everything including the rtl8188su that is not working anymore.
Can someone tell how to install the driver for rtl8188su from the bottom ?
It is impossible to tell you anything without the details of what you did. If removing the kernel module that already existed for this dongle/card then you need to download the .deb for it and put the module back in its proper place or re-install the kernel if not wanting to extract the file manually. If trying to correct the no n wireless then it will never happen the driver does not support it.
https://manpages.ubuntu.com/manpages/xenial/man4/rsu.4freebsd.html