Edit CG description

Hi,

How is it possible to edit the description of a CG?  I.e. on
https://www.w3.org/community/expath/, I'd like to edit the following
paragraph:

> The mission of this group is to lead to extension of XPath and all
> related technologies (XSLT, XQuery, XProc, XForms, XML Schema).

I tried the admin interface, but didn't find anything like that (but I
got a bit lost, I must admit.)

Cheers,

-- 
Florent Georges
H2O Consulting
http://h2o.consulting/