Mercedes sunroof

If there are screws on the front of the roof, it's probably just a cover over a main frame. Remove the screws and nearly close the roof. Put some gaffer tape or similar over the back part of the sunroof and on the roof at the front of it to avoid scratching them. Lift up the front of the cover and slide out forwards, easing the seal through the opening.

The rear fixings are usually just springs - it will be obvious when it's out.

You can now replace the seal.

When replacing, make absolutely sure you get the rear fixing strips under the springs - if you don't you'll scratch the paint when you open it.

A drop of washing up liquid etc should ease the seal past the opening.

Hope this helps as it isn't M-B specific, but most are similar.

I've replaced them on a W123 once. The front and sides are easy. Just open the sunroof and unscrew the sides. The front requires a very small amound of disassembly (I think). To replace the rear you need to remove the sunroof. The Haynes manual details the job reasonably well. Unless you really need to, just replace the front and side seals. New or old, they don't actually keep the water out completely, just the worst of it. I suggest you clear the front drainage channels with a tv aerial cable or similar. The rear ones are less often clogged. If water is dripping on your head or lap then rust may have taken its toll. There is no nice solution except to remove the headliner and patch things up with fibreglass - I've done it once, it worked.

Adam