To replace the Acer TimelineX built-in batteries like in the 4830T-6642 all you have to do is:
1.) Take out all the screws on the back and pry-up the track pad panel by using a flathead screw driver along it’s front and side edges. There are plastic clips around the front edge and both sides. It also has a hinge clip on the edge closest to the keyboard, so it has to rotate up and out that direction after you free it from the front and side clips.
2.) Unclip the 3 trackpad and keyboard ribbon cables. The ribbon cable connectors are fold up connectors, so just gently flip them up to release the cable.
I figured this out after snapping one off and had to fix it – thankfully it snapped right back together.
3.) Unscrew the 3 screws that attach the front edge of the keyboard panel and gently pry up the keyboard panel by working your way around the sides with a flat head screw driver. There are plastic clips on both sides and it rotates off towards the screen.
4.) Tada, now you can access the battery.
Replacements sell for $50-$75. Acer wanted $200 before tax and shipping.