Don't try replacing soldered RAM chips yourself.

Technically yes, but practically no — unless you own a BGA rework station and have done it a hundred times.

Soldered RAM (usually LPDDR) is attached with hundreds of tiny balls under each chip. Desoldering the old ones, cleaning the pads, and reballing new chips requires precision heat control, flux, and a steady hand. One slip and you lift a pad or cook the surrounding components. Even repair shops that offer this service charge enough that you’d be better off buying a laptop with socketed RAM.

It’s also not plug-and-play. The new chips need to be compatible with the motherboard’s memory controller, and sometimes the BIOS needs modding. Odds are you’ll brick the board.

Save the money and buy a machine with upgradeable RAM next time.