ok i ask because i have not a lot of time
...and you obviously couldn't care less about our time. The thing is, it will take less of
your time if you first RTFM, and then ask specific questions if there are specific parts that are unclear. It will also make us much more willing to help you.
With that said, though the wiki's instructions worked well for me, my ultimate solution was to stop using SME in server/gateway mode, and put it behind a pfSense router. I then configured the VPN on that device, which worked much more smoothly.