If its the LOWER LCD its probably fixable pretty easily but if its the UPPER LCD, buy a new DS! Or dish out the $100 for Nintendo to repair it, as its incredibly difficult to repair yourself!! As the ribbon cables are not just hard to get them rehooked up, its that there VERY DELICATE too and its very easy to tear one or more also then you going to need to buy new parts... Like I say having a authorized Nintendo repair service place is the way to go for a damaged UPPER LCD!
If you have to replace a upper LCD its probably worth it to dish out the $100 for Nintendo repair service as the ribbon cables are a pain in the (BEEP) to get them right and if anything is just a tad off it wont work!! The difficulty to do this correctly is BEYOND EXTREMELY HARD, its like almost UNIMAGINABLE to get everything back correctly especially the routing and connecting the ribbon cables!! Just ... If you have to use Nintendo repair make sure you haven't done to much tampering with your system for the repair service to detect it as if they do they'll return it to you indicating it was tampered with. As most companies wont repair (even if its outta warranty) a device that has been tampered with! Or if you don't care about loosing your games that you downloaded onto your DS, Id suggest just purchasing a new DS system all together as the repair of a upper LCD is like I say a TRUE NIGHTMARE!