After my passenger rear down to the ground , I decide to convert myself to coil spring according to Utahkompressor instruction and some idea from Josworth nember
So here's what I order :
Coil spring from MB part # 164 324 02 04 (2pcs), this is for ML coil , don't waste time to ask for coil from R class (they don't make it for America)
Upper retainer # 164 320 00 56 (must order from MB) 2 pcs
Lower retainer # 164325 02 15 (2pcs) must order from MB
Upper retainer plastic holder (2 pcs) I screwed up 2pcs , you better buy extra because once you lock upper retainer on it and you make a mistake , the only way to reposition it is to break the upper retainer plastic holder
Coil spring compressor , as Utahkompressor said :don't wast time to use conventional compressor , so I ordered spring compressor for Mercedes from Ebay ($169)
Rachet , sockets , ,wrenches , jacks (needs 2) and pry bar
Fist I ordered coil from Jeep dealer according to Utahkompressor but later I returned because I found bottom of coil didn't fit lower retainer , so I order coil from MB , also I have 2007 ML350 that has coil look exactly what I ordered.
Now you look at photos snd follow exact position how to set spring compressor , if you don't do it right , you can't remove compressor plates after you release because when you release compressor , the weight will apply on spring plates and make it impossible to remove
On the frame where the spring will sit on it , you will find a small slot , remember the lower retainer must fit in the hole and it must lock it in the slot , this will secure the spring in place
I used the thinest shim as Utahkompressor did , I don't carry heavy load on my car
It took me more than 3 hrs to position spring compressor to fit in the car and removed without hassle , the second coil took me only half hour because I already got experience , , that's why I advice you to position the compressor exactly as shown on photos , otherwise it will take you several hrs to figure it out.
I had to use second jack to lift up control arm so I could remove bolt on strut , this will give me more room to put the whole assembly in ( you have to attached upper and lower retainer on coil and put the whole thing in )
When you jack up control arm , be sure to lift it high enough to remove bolt easy , damage may occur if you bottom out thr strut.
Took me little more than 5 hrs to complete the job , test drive so wonderful , I am very happy not to worry about air leak anymore.
Remember to tight up both ride sensors to avoid nasty warning on board
Read Utahkompressor for further detail
I took lot of photos to save it for future need but unable to upload all , if you need more help , just send me email and I will reply soon as I can , I rarely go to MB forum so I may not know if some of you need help.
Finally I am greatly appreciate Utahkompressor who assisted me in finding the right answer at every email I sent , also thanks for idea of MB coil from Josworth