Just did this to my van.
Couple notes for next time, mostly for myself, since this is the first Google hit for "Sprinter EGR Cooler", and the OP did help.
1) OP is sandbagging by saying this job is "3 egr cleanings" - more like 10 or 20, IMO. But - not that hard to do..
2) A 1/4" drive E10 socket off Amazon was clutch, a couple extensions and a universal are nice too. Google "Amazon Stahlwille 40TX-E10". A proper hose clamp tool is nice as well - Google "Craftsman Cable Operated Hose Clamp Pliers". The job will take you considerably longer w/o the equivalent of these tools, IMO.
3) OP mentions 12 bolts and the cooler is out - BS, you won't get it out that way, you won't even be able to reach all 12 mentioned bolts w/o removing the whole assembly. His pix clearly show he removed more than 12 bolts - he took out the whole cooler assembly - which is the right thing to do.
4) 6 E12 bolts, 4 front, 2 in back hold the front / rear castings to the engine. 12x E10 hold the heat exchanger to the front and rear castings. The EGR is 4x E10. The dipstick is 2x E10. The oil filler is 1x E10. The exhaust tubes are 6x E10 total, 4 front, 2 rear.
5) There are 3 exhaust tube gaskets, 2 more for the heat exchanger, 1 more for the EGR. I suggest buying these ahead of time on the net. I bought local, paid ~$70. Yeah, they're just exhaust gaskets and if you're cheap you might get away with reusing them. But O2 sensors are nearby and are part of the warning for this problem - I just don't have time to screw around with air leaks getting in there and messing with the readings.
6) TETRIS: To remove cooler assembly, remove all but the 12 heat exchanger bolts. Pull the assembly free a bit, rotate a bit as needed, and disassemble it in place. I really don't see how one could get it out of there as one assembly, don't really see how you're going to reach the 12 heat exchanger bolts w/o being able to shift things around.
7) You MIGHT be able to get it out in 1 piece by removing a metal bracket in the lower front, and/or the coolant reservoir. This looked like more trouble to me. I had an ALLDATA procedure that did not mention this lower front metal bracket, just the above bolts. My official Sprinter shop manual CD (waste of money) is only readable on Windows XP at this point, and who has that old stuff laying around anymore...
8) Cleaning the heat exchanger is BY FAR the most time consuming part of the job. I refilled a Simple Green spray bottle, then cut the top off the remaining 1 gallon jug and dropped the exchanger in there. Soak - rinse - soak - rinse - repeat. There was a F'N F-TON of carbon in that exchanger. Holy Cow! It took a long time to see the light through it, much longer for the blackness to stop.
9) Pressure washer + simple green took care of the other parts. I removed the bypass actuator and pressure sensor before cleaning, left the door thingy in place. I also removed the rear temp sensor and O2 sensor and cleaned those up as well with a little water and some compressed air.
10) The sensors are fine, IMO, I'll post back if my codes come back. The blades on your EGR should rotate open. They are spring loaded, likely to protect the motor. IMO, 99% of EGR replacements are likely due to the tech being too lazy to clean the thing. I made up the 99% part. With the spring in there, I doubt the motors are burning out and you'd get a code for that anyway. The rest is just a dumb piece of metal. It's easy to clean, just take a few minutes.
11) TETRIS AGAIN: 1) Place front casting loosely where it belongs. No bolts. 2) Place rear casting where it belongs, no bolts. 3) Insert heat exchanger, attach to front casting first. Torque it down, you won't reach the bolts later. 4) Now attach the rear casting. Torque it. 4) The rest is trivial.
HAVE FUN..!!!
EDIT: Gaskets locally = 72.12 before tax. GenuineMercedesParts.com = 27.61 before shipping. Holy Cow - that's beyond an expensive local convenience - that's pretty much getting ripped off!! Still saved about $3000 though....!! Sometimes these vans are an expensive PITA...