permalinks

Hello,

I have finished and published my website.
You can see it here : http://www.nisiotis.fr/

On some pages, i would like to modify the permalink.
But i cannot.
For example, here :
http://www.nisiotis.fr/portfolio-item/danse-musique-et-tradition-a-tinos/
I would like to take off “portfolio-item”, and just let :
http://www.nisiotis.fr/danse-musique-et-tradition-a-tinos/

How can I ?

The same for those other pages :
http://www.nisiotis.fr/portfolio-item/marbre-et-sculpture-a-tinos/
http://www.nisiotis.fr/portfolio-item/le-monastere-de-kehrovouni/
http://www.nisiotis.fr/portfolio-item/la-nature-a-tinos/
http://www.nisiotis.fr/portfolio-item/les-eglises-a-tinos/
http://www.nisiotis.fr/portfolio-item/pigeonniers-de-tinos/
http://www.nisiotis.fr/portfolio-item/architecture-de-tinos/
http://www.nisiotis.fr/portfolio-item/divine-mer-egee/
http://www.nisiotis.fr/portfolio-item/paysages-de-tinos/
http://www.nisiotis.fr/portfolio-item/le-pelerinage-a-la-vierge/

how can i take off the “portfolio-item” in the PermaLink ?

Thanks !

Philippe