It was very simple and there was no need to solder anything. In order to upgrade the CPU, all you have to do is unscrew the bottom plate, and then unscrew the full heatsink/fan apparatus. The CPU should come out fairly easily. Note that the latest CPU the Travelmate 8204 would take is the T7600 (which is still several years old, but is a Core 2 Duo and is newer than the Core Duo I had in there). There are two kinds of T7600s - the SL9SD and the SL9SJ. The D means it’s the socket variety (the kind you want) and the J is the kind that’s soldered directly on the board (which you don’t want). Some of the ones being sold as SL9SDs on Ebay are actually SL9SJs with an adapter on the bottom that adds the pins and effectively makes them SL9SDs, but I was wary of those and made sure to buy the original socket variety.
The RAM is in the same compartment as the CPU and is easy to get to.
The HDD is in a seperate compartment that is easy to open, just make sure you screw the carriage off the old drive and put it on the new drive, it helps disperse heat.
Many thanks. The trend is towards making laptop’s vital parts more accessible. I see this on my own modest Compaq I got two years ago. I can get at the HDD and memory very easily. I’m going to look at hard it is to get to the CPU even though I have no plans to upgrade it. Its CPU is something like T2310 Dual Core Intel