This guide worked really well for me, apart from the expected slight glitches which are par for the course (see my comments on Step 20). A useful tip is to use an ice cube tray for the screws/parts - as you take them out, put them in a cube well and mark it with the corresponding Step number. Makes it easy as you go in reverse order to reassemble.
As I tried to refit the optical drive, the plastic mount for the brass threaded socket that receives the screw crumbled like an old tooth. Only thing for it was to ditch the plastic and superglue the brass socket into place on the case - seems to have worked. (People who design parts/fixings that involve strong materials held in place by weaker ones should be imprisoned). I also had to remove the sliding bracket on the drive and cut 2/3mm off the right hand end to get the screw hole to align with the brass socket, also seems not to have caused any harm. Never thought I would find myself lashing out with the superglue and wielding a hacksaw inside a laptop...empowered!