Can this replace my dead gpu?

Well technically yes, you can replace it, you have to have a number of expensive tools, and plenty of experience using them.
To properly replace it, you would need a BGA chip replacement machine (these are a combination of a fancy heater that gives consistent heat to just the area of the chip and to the board where the chip is, and is able to accurately control temperature curves to ensure a proper solder joint. The upper heater is also attached to a Z axis that can be lowered exactly where the chip should be.
Not to mention, you don’t know if the new chip will have pre-attached solder balls, so you might have to get solder paste and a stencil for that specific chip.
The spot on the board from the old chip has to be cleaned with a soldering iron and solder wick to make all of the pads flat again, and you would also need flux for attaching the new chip.

So in the scenario that you do have those things, feel free to try it out, otherwise you’re probably just wasting money on a replacement chip of dubious quality (those chips aren’t supposed to make it to market anyway), instead of spending it on a new motherboard. While doing the repair without some of those tools is potentially feasible, the chance of it working is incredibly slim. That isn’t even addressing the likelihood that it stays working, especially after applying pressure from the heatsink.