If you can get the sunroof to open, you can sometimes work from the top down. Remove the metal stock wind deflector and it should reveal the motor driven gear where it engages the cables. There are two rivets on either side that attach the cables that often come loose. Replace them with pop rivets or self tapping screws and use a faucet washer over the gear to keep it inplace. My sun roof was jamming in the rear raised position and I fixed it in this way. That was six months ago and it is still doing fine.