Hey there,

A new screen as in the hardware screen or the cover screen that protects your iPhone from your finger prints?

If it is applying the screen to protect the actual screen from your finger prints, there is a website:

http://www.ehow.com/how_5942211_put-scre... (credits to them, I did not write this, although I wish I did =P)

If you're talking about the actual hardware of the iPhone screens: I suggest you take a look at:

http://www.wikihow.com/Fix-an-iPhone-3G-... (If in this case, you want a screen replacement)

[[iPhone 3G Troubleshooting]] (Some of the frequent problems that occurred on iPhone)

And there are also some resources about taking the iPhone apart and replacing it with a new screen on the ifixit.com

Installing iPhone 3G Front Panel

Things you might need to buy:

iPhone 3G Front Panel Kit

I am sorry I can't actually help out with my current resources, but If I am talking about something totally different, you can re-post your response and I will do some more research about it.

I hope I helped,

thanks!

Nonth =)

When installing a new screen its best not to remove any protective films untill right before you put it in.

I find that using a microfiber cloth tends to work best.

After wiping it down, keep it covered by the cloth, and then wipe the LCD with the another cloth.

Then (as i said above) give them both a quick wipedown and install them.

By wiping them both right before you close up the iphone you are making the time it takes for dust to accumulate shorter and therefore eliminating most of the dust under the screens.

Hopefully this will prevent any dust getting in, but its not fool proof. Its just alot of trial and error.

Hope this helps!