I recently had to revive a ML850. Having lots invested in docking these I figured I might as well document what I had to do and take some pics to hopefully ease the pain of others. First to disassemble these you have to remove the bottom “pan” from the unit. The only two hidden screws are underneath the battery. You only need to take out the case screws and not the rubber cover screws. At the front of the pan there is a place to place a small flat head screwdriver to gently pry the pan off. The pan also has a wire that needs to be disconnected.To remove the hard drive its just a matter of gently prying the Mylar connector up and working the drive out. There are no screws holding it in. Its a compression fit and the caddy just untapes. Be careful to save the tape and keep it intact. Now on to the pics. If you have questions please ask. If you have any info on putting a GPS in the ML850 please contact me, I’m very interested in doing this.