while dis-assembling it is OK (it is like chakravuya in Mahabharata),
1. Remove all the Screws, double check for sure, remove the power button panel, then you can remove keyboard do not pull it out immediately there will be a strip cable connected to the motherboard remove the locks to pull the strip cable, once you remove the strip cable you will see some more screws & strip cable from touch pad remove it, remove optical drive by pulling it out, disconnect LCD display cable & any other cables which are coming out of top LCD panel, remove top LCD panel by removing few screws near the two hinges in the bottom casing.
2.take care not to break laptop casing when separating two panels of bottom,
3.while assembling take care to put screws back where it was removed because there will be different length & size you may short the MOBO if you tighten it in a wrong place.
i have seen lot of laptops going dead, i dont want scare you guys, but be careful