I volunteered to update an old Inspiron Mini 10 netbook (or whatever they called the things) with Mint Linux and wanted to see what replacing the dead-slow 5400 rpm hard drive with an SSD would do for the struggling Intel Atom Inside. Dell provides a Service Manual showing how to remove the three screws on the bottom of the case, then gently remove the keyboard (!) to get access to the innards.
You start by covering the screen with some low-tack plastic film that you’ve been saving for this very purpose, sticking a small screwdriver into the center screw hole, and pushing the keyboard firmly away from the case. This bends the keyboard enough to get your fingernails underneath, after which you can pull / pry it away from the latches on each side.
The left side of the keyboard (as seen from the normal vantage point) comes out first, after clearing a small latch just over the single left-side USB port:
The right side pops free from its latch over the HMDI port when you push the keyboard firmly to the left:
Then release the keyboard’s ribbon cable clamp, pull the cable out, remove the keyboard, remove the single screw holding the hard drive carrier in place, and swap drives in the obvious manner.
Conclusion: an SSD helps a lot, but Firefox on an Atom CPU remains pretty slow off the starting blocks …