Hi, I need to replace my LCD, but searching in other websites I found that there are 3 differents parts numbers, XX2337, XX2338 and XX2339.

It could be possible to know the correct part number without open the cellphone?

maybe with the serial number or maybe with pin's number?

thank you!

nope.
part numbers are on the back of screen. (generally)
as you have to open it up to change it, open it up to order the correct one.

or order all 3, and send 2 back.

Wirelessly posted (overwhelmingly stressed)

Or contact www.horizonwirelessonline.com. Bet they could help ya figure out which screen to get