Finally got round to looking at the same problem on our 2005 CRV. Removed the unit, two screws up under the air vents. Pull out trim and then four bolts retaining the unit. Pull out unit and remove several plugs.
Remove mounting plates on sides of unit and large black box hanging on these and plugged into back of unit. Removed the rear cover (about 10, screws didn't count) then lifted top off. Removed the screen, 4 screws. Seperated DVD from CD (another four screws I think). Then I may have started removing unecessary parts and you may see a better way for the next steps. Took the circuit board off the top of the DVD but this is held to the unit by ribbon cable that can't be detached. Then removed plate on back of DVD held with very small screws and springs. Did not detach springs just gently moved plate up. Then by shining a tourch in the back I could see the laser through gaps in the top of the unit (with previosly mentioned circuit board held to one side). Once the laser was found it was simple to put some cleaner on a cotton bud and reach it through the open back of the unit.
Reassemble. Then wonder why you have two screws left. Take apart again and then realise you miss counted and they were the ones that held the top on.
Any way it works perfectly now.
Craig
December 2008