No, you dont need to remove the whole dash. Just the panel around the clocks that the switches mount to, so you can get at the fixings for the clocks.
As I said, pry off the various switches (lights, heated window, and the blanks) on the face of the dash. I think you pull out the lower edge of the switch first iirc, then it pop's out easily. Pull off the heater slider arms and fan knob, pry off the heater control. As you remove this stuff you reveal the screw fixings behind that are holding the clock surround/dash panel in place. Remove the various screws, taking care not to drop them into the lower dash various, then remove the panel. Take the steering wheel off too to make this possible (so make sure the wheels are straight so it goes back on straight). You can then get at the screws and plugs on the clocks to wriggle them out.
Its not as bas as it sounds, It can only take 10mins to get the clocks out if youve done it before. Just dont loose any screws. Its all fairly solid stuff, but do take care not to break any clips/mounts while your at it.
Does that make sense?
there are links to service manuals (haynes and bentley) in the maintinance section, they may have a fuller description with pictures for a better understanding.
