I replaced the motherboard in an IBM 600x. It was really easy to do. Unlike other laptops, the parts were easily removed and replaced. It took me about an hour and a half. I've worked on Sony's, Compaqs, and Fujitsu's but the IBM has been the easiest of all to work with.
Ofcourse, the models do vary so take my experience lightly.
But you know if the motherboard is bad, how much do you have to lose by pulling the machine apart? At the minimum you will have learned something.
If you aren't confident or organized, then I'd take it to a local computer repair shop.
Tools, work area, recording screw and part locations are all critical to successfully restoring a dead laptop.
Good luck!