How difficult is it to replace an alternator and what's the most important thing/things to remember while doing so

Not always. You might have a large parasitic drain on your battery when the car is not in use. Secondly you can test your alternator with a multimeter simply by first, making sure your battery is charged, then starting your engine and putting the meter on the battery terminals. If the battery is reading around 14 volts or higher, it's taking the charge from the alternator. Alternators are basically two or three bolts and an electrical plug in the back of it.

You can also take it to Autozone, Advance Auto, or O'Rielly/Pep Boys for a free alternator test. Replacing an alternator is simple, but you'll have to back the serpentine belt off by placing a socket on the tensioner and turning it until the belt is loose.

if your battery is lasting 3 days, it isn't the alternator- with that Benz, you should have a good Mercedes mechanic- why have an expensive, complicated car like that and try to be fixin' it yourself?

I'm a student and wanted a luxury vehicle to play around with and enjoy what's left of my youth, but didn't realize how much it has been costing me just to maintain it... Every sensor alert and every service requested I'm usually in the Mercedes shop taking care of it right away.. The vehicle had a great track record, but in my current situation(graduated from college but can't catch a break in my job search) has left me ima super tight budget.. I actually have this beautiful machine posted for sale just for that reason, if ur interested.... But I appreciate the feedback thank you

I had the same problem of me 13 year old Merc C230k now. All workshops I went enquired suggested alternator changed, however, from me previous researches it could have been just the alternator's control unit that sits above it that is most likely faulty as Merc's alternator failure is not aa common.