i know 2 ways to do it, first is by removing the camshafts, rocker arms and then remove the lifters.
for that you need to remove the valve covers, remove the oil line above the cam shaft ( may require you to replace the plastic peices on it ), remove the timing chain pully that are fixed on the cam, just mark the chain and the pully and the cam. so when you want to return it, you wont be lost.
loosen up the chain tensoiner. remove the pully, ( impact gun would be perfect ) using a screw driver to stabilize the pully. then tie up the chain, and make sure it doesnt fall inside the engine..
pull the cam shaft to the rear of the engine ( by gentle tapping, untill u free the rocker arms. after that its just physical strenght to remove the lifters. ( impact gun would be perfect here also ) its size 22 mm. put oil in all of the lifters threads before fixing the new lifters.
fixing it back again requires you to replace the cam shaft in its position. then insert the rocker arms beneath the cam, fix the valve end, while the end that fits on the lifter is loose. then lift it up by using a wrench for levarage ( put the tooth of that wrench inside the groove that should fit on the lifter ). and let it rest in its place.
make sure all in place.
fix the chain on the pully on the cam in the same position,
fix the oil line on top of the cam. tighten to the torque.
do the same for the other cam.
re tighten the chain tensionar.
it is advisable here to turn the engine clock wise 1 or 2 turns using the crank shaft screw ( size 30 i think, inside of the crank pully )
and see if everything is fine.
the second way. would be easier, it only requires you to remove the rocker arms by rocker arm pressing tool. no need to remove the cams, nor the pullys.
the wrench maight be used to help removing. but it sure comes handy when ur fixing the new ones. make sure u lube all the parts with new engine oil. and good luck.
i hope i didnt forget something.

 

Thanks a lot for the reply!

The actual problem I am facing now with everything disassembled is the following. See this lifter from the internet:

It's top ring has small dents. These prevent the lifter from getting in the rocker arm. This one has the ring completely flat, so would fit smoothly I guess.

The ones I bought have those dents and the lifters just won't go in.

I don't understand... how can I install them?

Thanks

 

i really donno about the ones that you show.
but of the 500/560 this is how the hidraulic lifter look like.

 

I had lifters replaced last summer and in 3 weeks I heard the ticking from them again. I called the shop about it and this time the owner was in and he said you should always replace the lifters and the cam shaft at the same time because the two adjust to each other and are "mated" for life.

I don't know how accurate this is, but they replaced the lifters and this time replaced the cam shaft and it's been fine ever since. Since he wasn't interested in supplying the lifters for free the 2nd time out because his foreman didn't "know" you replace both at the same time (which meant I paid for the lifters 2x due to that) I'm now using a different mechanic. Instead of the nice businessman who does the diagnosis then has one of his 8 mechanics work on the car, I found someone older and more experienced who runs his own 2 person shop where he does much of the work himself. Doesn't cost as much and he seems to me much quicker and more accurate.

 

Ok,

found it myself the hard way.

Those marks, not there in previous versions of the same lifter, lock the lifter so when you remove it gets destroyed. When removing it the ring with the marks will detach from the lifter.

Now I need a new lifter...

Argh!

 

Oh wow!

I am really NOT replacing the camshaft. Hope I solve it with the lifters...

Thanks anyway

 

Bereng, your M103 engine is an entirely different animal as compared to the M110/116/117 configuration the majority of us here are familiar with. As such none of our advice is worth much in this instance. My suggestion to you would be to introduce yourself over at the W124 and W126 boards where engines such as yours are far more common and I would expect the advice to be far more pertinent.

 

I've heard it is a good idea to replace the timing sprocket when you do the time chain b/c the old sprocket will eat up the new chain. Don't know the truth to it, but if the parts mate like you folks are talking it is entirely plausable. Good luck Bereng!