Hej!
On the top of your site, the alternating values are already m/s.
I say it is only the graph you need to change. Am I right?
The chart is generated in the meteobridge from a template-file.
To change the graph, you will need to change the template-file.
Log on to your meteobridge file system. Go to data -> templates. There you find a file called allinone-iso.chart.
I have myself already made this change to m/s , so feel free to just copy my file. Download this and put it in the same template-folder.
https://fishmoose.se/slask/allinone-iso-mps.chart
Now go to the web interface of your meteobridge, go to services -> events and change the chart generating template to this new allinone-iso-mps
...
I do not know if you also use the min-max chart, but feel free to download also that template, I have changed also this to m/s:
https://fishmoose.se/slask/allinoneminmax-iso-mps.chart
....
NOTE! Another option is to use the metachart option in the meteobridge. With that you can make the layout and contents of the graph the way you want. (See attached screenshot) The name you enter at the top, you then choose as template in the settings->events.
(However, I think that using my file above is the fastest solution)