This is straight forward but involves a lot of screws. In the first instance I was helped as my unit had two-thirds of the front panel missing, and, as always, looking round you'll often find one screw with a 'warranty void if...' sticker or similar covering it.
First you need to remove the side panel on the left-hand side looking from the front. There are three screws holding it in place.
Next you need to remove the front panel. Here I have a bit of guesswork as my front panel had been damaged and two-thirds of it was missing. The remaining end of mine had a small lip on it that slotted into the edge of the side panel. I assume that an identical lip was on the other end of the front panel. The exposed front on my unit had traces of double sided tape. I don't know if the tape had ben there from the start or were there as a 'repair' after some ham-fisted person broke the original front panel.
Having freed one end of the panel by removing the side panel, if you are lucky your front panel will just lift away. If double-sided tape is present you will have to gently prise it off starting from the freed end remembering that the far end is still trapped by the other side panel.
Next you need to remove the three screws at the bottom of the front panel and a similar three screws at the bottom of the back panel after which you can remove the bottom of the case.
At this point you have access to the mPCIe sockets and the RAM SODIMM. If you want to get at the SATA socket that is on the other side of the circuit board you will need to remove it.
You now need to make a decision. Either way you need to remove the three screws holding the rear panel to the top of the case. (There is no need to disconnect it from the circuit board). After that you have the issue of the connection from the wireless card to to an internal aerial on the front panel. You can either disconnect the aerial lead from the wireless card or remove the three screws holding the front panel in place.
The circuit board is held in place with six screws. Note that two of these (the ones with insulating washers) are very short. Remember where they belong.
Caveat: I'm describing my example which no doubt has been fiddled with a number of times before it reached me. By now screws could be missing or fitted incorrectly. (I can see a point where there might have been a seventh screw).
As always you just reverse the process.
I removed the front and back panels when I took mine apart. When you come to refit the front panel you'll find that it drops into a slot in the top cover. It took me a little while to get the end nearest the on/off switch to locate in the slot. You'll know when you've got it right as you'll be able to fit the screw at that end of the panel. I refitted the front panel after fixing the motherboard in place. Maybe I should have fixed the front panel first?
Any comments? email me. Added April 2021