Leaking strut
 

I put the left side of my 07 SL550 up to replace the front brakes . It was up overnight and when I came back to the car the next day I noticed a small puddle of hydraulic fluid under the left front strut that was not there before I jacked it up. The car had been in the same position for 2 months due to winter storage without any leaking or drooping. Could the full extension of the strut while under pressure have caused this .

Possibly, or a hose, or fitting. I've never heard that jacking a car up caused a leak.
Clean things up and see where it is coming from.
Then replace whatever it is. I've done 2 struts and all of the accumulators on mine.

If you start the car you'll see where it's leaking but be ready to turn your car off it could get messy

It looks like I am going to have to replace the strut. I found a video from Arnott and it appears to be a simple procedure however it states that an SDS is necessary. Is that true or not? I have done multiple searchs in this forum and have not found anything about the procedure . Can anyone offer some help.

SDS is not required on my 2003 to replace a strut. Not sure about later models, but I doubt it.
You need SDS to do a rodeo, but rodeo is not required either.
Plug and play, cycle the system with the internal button, change the fluid if dirty.

Thank you, that is what I was hoping for.

be prepared to battle the 'quick disconnect' line that comes out of the strut (it essentially is the same as the end of an air compressor hose where you have to pull back the collar to release). my front two were rusted and it took 4 hours for me to get them both off. make sure you have a lot of penetrating oil to spray in there.