To the best of my knowledge, this isn't done anymore. Some chipsets might be altered by flashing new instruction sets, like you do with BIOS, but this is rare. The chipset and the motherboard are a matched pair and its normally hardwired, not socketed, into the board.
The chipset is integral to many features of the motherboard, providing linkage between the processor, the graphics functions, the memory and the bus. It's the basic fingerprint of the motherboard - allowing it to work with various CPUs. The BIOS can be altered by updates to allow, for example, newer CPU support.
Generally, the motherboard's model number is based upon its chipset. I don't know MSI numbers, but let's assume the K8 is the socket and N is Nvidia and...