Done this tons of times & there are 2 ways.
Correct way is take the phone apart as there are tiny lugs on the side of your lens but that's too long winded.
Best way is to get a tiny stanley blade & start at the top near the speaker, pop the blade in at an angle so it's almost flush with the lens & start to lift the lens, just go round it like you are peeling a potato, starting at the top then doing both sides.
When you get to just the bottom that needs doing lift the lens from the top so you can see where the touch screen buttons are & gently cut the double sided tape so you don't damage anything then the whole thing just lifts off.
When you put in your NEW lens use your stanley blade to just take those tiny lugs off the top & sides of the lens so it will just pop in without marking your fascia & you're done.
The lugs do NOTHING as the double sided tape is re-used & seals the screen fine, must have done 30 of these all the same way with no trouble whatsover.
If you want to you can also use a hairdryer & heat the front lens to make the double sided more subtle, i've never done this but you can do if it makes it easier
:o)
Craig
GATORS, November 2008