It can be a major project, but a good learning experience. After removing the old motherboard, you will need to remove the fan and heatsink from the processor. Do this with some care because sometimes they stick together. I'm assuming you are using the same processor. If so, you will want to clean off the old thermal compound on your processor and apply fresh compound (arctic silver). The new motherboard may need new memory. After everything is hooked up again, windows may freak when it wakes up with a new board. A repair windows installation may be needed. . . but I've usually gotten better results with fresh windows installs after a motherboard upgrade.
Have fun with it!