Is Compaq laptop can be upgrade its GPU?

Not all laptop GPUs are soldered; some high-end models use mobile GPU modules. As for replacing the ASIC itself, any more powerful GPU you might find in the same power budget would likely have to come from a newer design/process generation and those pretty much always have different pin-out.

Wave-soldering (passing boards over a fountain of molten solder) is for through-hole components; it would likely pluck surface-mount components right off the board. For BGAs, you need an IR soldering oven for reflow soldering.

The BGA chip removal, board clean-up and soldering job costs a few hundred dollars as a one-off lab job which is already likely far more than what the laptop is worth and there is no guarantee that it will work.

Even if OP has a modular GPU, it is quite likely that the most powerful GPU he could find that fits in his laptop would cost more than his laptop is worth.

In general, upgrading laptops is simply not worth the trouble due to extremely limited component choices aside from RAM and HDD/SSD and nearly everything else either being soldered on-board, proprietary or locked-out by BIOS.