I've got to say I have removed my dvd drive and found it reasonably easy,unfortunately I didn't take any pics.but I basically unclipped the gear stick surround first,opened the cig lighter cover,pulled out the ashtray,undid all the screws I could see (I think there were 4 of them)after pulling the plastic covers off from below the satnav screen it revealed 2 bolts and 2 nuts,I removed these using a socket with extension bar and I'm pretty sure it was a 10mm socket.i then placed a soft cloth over the pieces of shiny plastic at the bottom to protect from scratches,I pulled the drive out and removed the 3 cables from the back of the unit.After taking the unit out I placed it on a newspaper on my kitchen table,got a small posi screwdriver and removed the 2 gold screw on the back of the unit,this allows you to lift the top up from the back and carefully pull the top from the front clips,after doing this you will be able to shine a torch through some of the apertures and you should see a purples,bluesy reflection,this is the lens! You will carefully be able to reach the top of the lens with a cotton bud ( I put some DVD cleaning fluid on mine)
After this put everything back in reverse order,simple! This took me about 1 hour.
I would love to tell you there was a happy end to this but the read error was still present.
Plan b was me removing the unit again ,sending it to Dtronix in Milton Keynes,paying £179 to have the laser replaced which took about 3 days and everything is now fine!
A bit of a long winded reply for you but I thought my experience of the same problem may help.