To remove the Top dash you do not need many tools, but you do need patience, flexibility & a methodical approach. It would also be a good idea to place the fixings as you remove them into a bag/box with compartments & label them as there are so many differnt types that look similar when you come to replace them.....Doh
I found the way to start is:
1. Remove the metal finisher together with rubber seal just next to the windscreen (3 screws) but be wary when lifting out as it very easy to bend.........Exhibit A:-
2. Working down then remove all the pieces of trim, sides/steering column/centre console/glove box/speedo etc as per ...........Exhibit B:-
3. This will expose the main fixing bolts around the outside & at the end of the dash.......Exhibit C:-

4. Now loosen all the cable fixings holding the looms to the dash (some have screws) .....Exhibit D:-
5. Now comes the hard part, there are 5 x 8mm nuts that are underneath the dash both sides of the centre Air Vent ......Exhibit E:-
6. I used a long flexible socket extension to remove these, you will need a torch to locate them
7. Once you have removed these, pat yourself on the back & go down the pub
8. Now comes the Extremely hard part, there are 2 x screws located at the back centre that are INSIDE the heater box

I accessed using a 90 degree toolly thing & tilted the Dash forward

........Exhibit F:-
9. The dash should now lift out, carefully, there may still be something attached that I did not have/broke (I did not remove the steering wheel, but it would have been easier).
10. Go back down the pub
11. Installation is just the reverse.
I DID THIS OVER 2 DAYS..........AND.......... ON THE THIRD I ACHED! (BUT FELT SMUG)