Ok, although I've seen a text 'how to' I thought I'd post a quick picture guide. It's really simple, even for those of you that get scared at the thought of even holding a screwdriver.
Start with this. Tools required? 1 Phillips-head screwdriver, daylight and patience.
2. Remove the ashtray and you'll see this:
3. Remove the two screws (already done above). Put to one side - you'll need them later!
4. Gently pull the bottom left hand edge away from the main dash. It comes away quite easily, so don't yank it hard, just ease it out!
5. Now get your fingertips (you don't need a screwdriver - you'll only scratch your dash) and pull gently at the top of the dash - this is barely held in place with plastic latches - so it detaches away from the main dash.
6. Like so..
7.Until it all detaches thus:
8. The best way I've found of detaching the two electrical connections (hazard warning light switch and the cigar lighter socket) is to twist the dash slightly, like so:
9. First is the Hazard Warning Light. Press the top of the plastic connector down (arrowed) with your fingernail or a small screwdriver - it has a small latch that stops the connection disconnecting during normal driving. Once the latch is depressed, the connector should come away easily. If it doesn't, you haven't hit the right spot for the latch! Just be patient and you'll find it.
10. Now you've got a bit more room, the lighter socket simply pulls away from the two metal spades, but it can be stiff, so try and get both hands down the gap and hold the socket AND the connector as you pull the two apart.
11. Now you can wiggle the dash out around the gear shift/lever, and you're done. You can now see how the stereo unit and pocket tray(s) are connected into the main dash - four self-tapping screws (two indicated here).
12. Undo those and you can gently extract the whole unit. As you can see it's all held together by two metal side plates - the stereo and the pocket trays are screwed into these.
13. The car has these connectors going to the speakers (front and rear)
14. So you need one of these (search for "Nissan Micra ISO Adaptor" on ebay - I've used a company called LiquidICE for this and they were good value and quick - http://eshop.liquidice2008.co.uk/epages/BT4177.sf/en_GB/?ObjectPath=/Shops/BT4177/Products/"PC2-76-4 Nissan Navara Micra X Trail"
) to connect your stereo unit to the speakers.
15. The pocket tray is attached here via one screw (indicated) and a plastic locating plug.
So, once you've sorted your stereo, replacing your dash is simply a reversal of stages 1-11. There's so much space behind the dash for a stereo unit that there's no problem about having a load of leads and connectors. The unit you see in the pics (JVC NX7000) has the speaker connectors, the aerial lead (which is the unit earth), a bluetooth lead going to a bluetooth transceiver located under the steering wheel, a GPS lead going to a GPS receiver under the dash, a video lead coming from the reversing camera and there's still loads of room.
So, don't be afraid. Get under the dash!