This is indeed an enourmous task. Eighteen or so hours by professional labor guides. If you are not well experienced with simpler/quicker replcements of such on other vehicles, then you have quite the project ahead of you. Last one I did took about fifteen hours total, and I have done a few of them. Times include evacuate and recharge.
FYI the first benz I bought I got a great deal on as the owner did not want to pay to do this job.

If you are without photographic memory:

get ziplock bags and a sharpie-Label and separate pieces and parts.
take a few notes as to the order of disassembly.
do not get in a hurry with old/brittle plastic parts.

For ease of work area start by removing the front seats, carpet and console:the job can be done without this but it actually takes more time.
Replace the rubber vac boots and pods while the thing is apart.
Let me know if you need assisstance.