[1] gives a very good rundown of what you need to do to make it work. It is actually very trivial (once you've got wireguard.ko). Just generate a key, and cross-copy the public halves.

However configuration to make forwarding of all packets and thus making it usable as a full VPN requires a few extra steps on the server:

    * net.ipv4.ip_forward = 1
    * net.ipv4.conf.all.proxy_ARP = 1

And on the client, especially if you're using wg-quick:

    * AllowedIPs = 0.0.0.0/0

But it shouldn't take that long. I got it working in tens of minutes.

[1]: https://www.wireguard.com/quickstart/