I saw we can download items in the download section ( duh ). but I don't know how to use them, anyone can help ????

You need a char editor. Same general area.

You cant use the items on Battle.net. The hero editor will only work for single player.

you use an editor, and then access the downloaded item from there

ok and can we use it for battle.net ?

No, those items are strictly for Open B.net and Single Player. If those items were able to go on Closed, we'd all be rich heheh.