Don't try desoldering laptop RAM yourself.

Technically yes, you can desolder and replace a BGA RAM chip on a laptop motherboard. But unless you have professional rework equipment and steady hands, you will destroy the board.

The chips are small, tightly packed, and soldered with hundreds of tiny balls under them. Removing them without lifting pads or shorting adjacent components is hard even for people who do board repair daily. Replacing with a higher-capacity chip also requires compatibility with the CPU’s memory controller and often a BIOS update. It’s not like swapping a stick of SODIMM.

If you really want more memory, you have three better options: buy a different laptop with more soldered RAM, use the swap in RAM or page file tricks (slow, but work for light tasks), or accept 8GB as the ceiling for that machine.

This is not where you save a few hundred bucks by DIY. You’ll end up with a dead laptop and a lesson.