|Too complex and protracted to talk someone through the full process in detail. |
All laptops are different. Some can be quite difficult to strip down and rebuild to/from motherboard level. It's easy to cause permanent damage to the likes of the ribbon connectors and such; some are 'wedge-locked, some a locked by means of tiny flip hinges.
Normally such a repair on an old laptop like this (2007?) would be regarded as, beyond economic repair, but if you've nothing to lose by it and maybe got the replacement board for nothing, then give it a go. It's a good learning experience.
Fortunately, Dell are pretty good and provide a service manual for this model.