Hi,

is it possible to change the articole linked to a k2 content module from the frontend?
Thanks

Try turning front end editing on, putting the user in a k2 user group that can edit own or all items.
Not sure about items that are displayed by mod_k2_content, but in the standard category and item view there is an edit item link, which could most lilkely be added to an override of mod_k2_content