Hello Cees and Naj,
It is tricky getting those systems in and out in one piece without a lift. Try jacking up just the back of the car first or jacking only on the right side. You must achieve the correct angle to insert or remove the front pipes by themselves. When you are ready to install the system. Load the suspension on all four wheels. Assuming you do not have a lift, old car wheels work good as jack stands under each tire. Stack a 13" diameter on a 14" for more altitude. Or, you can also place jack stands on all four corners of your suspension to load it correctly. If you are installing a new totally welded up system put the front pipes temporarily in place before connecting up the rest of the system. Use jack stands and hangers to temporarily hang and position the rest of the system. Once the exhaust is positioned exactly correct (check for clearence and position), tack weld the entire system in place so that it is rigid. Next, unhook and drop the system down as far as possible so you can weld it all around each pipe. If you are not on a lift you will not be able to remove it completely, but far enough to weld. Re-install the system as a complete unit. It is a lot of trouble but is worth it. You will get a permanent, quiet, rattle and vibration free system installation which you will enjoy for years and years.
For removal without a lift, try lifting the car about 45 deg. on the right side only with the tires on the left still on the ground. Some guys jack up just the rear of the car with the front tires on the ground. You will have to unfasten or cut the pipes at the connection near the transmission. I will try to find my original installation instructions and add them to the string.
If you have a 230-SL with the header style manifolds, the system will drop right out or install without all these special procedures. Good luck Cees.
Joe
Joe Alexander
Blacklick, Ohio