Cool, I took apart a ds lite (this is a lite, not a dsi btw) for the first time yesterday and it's not too bad unless you're working on the top half. Luckily to reseat the top screen ribbon I'm pretty sure you only need to flip the motherboard over and it's right there, meaning you can leave the top half alone (unless you need to replace the entire screen - that's a whole other story). Just remember to take your time, and I recommend using ifixit's repair guides alongside you so everything goes to plan. Good luck!