Based in large part on the WindFinder extension written by Matthew Wall.
Register your WindGuru station https://stations.windguru.cz/register.php
Download the extension
wget wget -O weewx-windguru.zip https://github.com/claudobahn/weewx-windguru/archive/master.zip
Run the extension installer:
wee_extension --install weewx-windguru.zip
Update weewx.conf:
[StdRESTful]
[[WindGuru]]
station_id = WindGuru_Station_id
password = WindGuru_Password
Restart WeeWX
sudo /etc/init.d/weewx stop
sudo /etc/init.d/weewx start