There are several screws in the computer, begin by having a clean workspace where you won't be losing screws, but can keep screws separated so you know where to return everything. I'd start by removing the plastic molding at the top of the keyboard-take a small flat-head screwdriver and gently pry the piece right above the F1-F12 keys, working across the keyboard. Once this is off you'll see several screws holding the keyboard in place, remove these and set these to the side where you'll remember what screws went where. On the underside you'll see ~21 screws that will also need to be removed and set aside, remembering where to return them. Once off you should be able to gently pry the casing apart and get to the motherboard/power adapter connector, make sure the battery is removed and the AC adapter isn't plugged in before touching any components, and be sure to ground yourself (touch something metal and make sure you don't have any static electricity built up before touching inside components). Lastly, be careful what you touch inside the case, there are capacitors which hold residual charges, and other sensitive components that can either shock you, or easily be messed up. My opinion is that if it still charges at all, keep using it until it's absolutely necessary to fix this issue-it may require soldering pieces back on anyway, which are usually beyond the skill level of most humans.