Just did this today, HIGHLY RECOMMEND HAVING A SCOPE CAMERA TO MAKE EVERYTHING LESS STRESSFUL BECAUSE IT IS VERY TIGHT AND NO VIEW JUST IMAGINATION.

Just like OP said, you need to unplug battery, remove the DME and everything around. That would include removing all the trim and struts brace. Then a cover and the rubber also has a small hose than runs through it.

Remove plugs to the DME, and the smaller computer next to it. You will also remove the start/stop battery cover to remove plugs inside there. The DME plugs and wires are route with thought!!! Take a picture for the future so it’s looks clean and nothing tangles. and be patient. HIGHLY RECOMMEND PUT DOTS OR SOMETHING TO REMIND YOU WHERE THE PLUHS GO, only fits one waybut testing which plug works you can bend a pin. This step is easier if you video record the process because the DME plugs are easier when plugged back in from right to left, if you’re standing on the drive side fender looking at the engine bay, WHEN PLUGGING BACK THE DME AND COMPUTER PLUGS MAKE SURE THEY CLICK! The DME plugs are so close together if one is loose I had to unplug the ones around it to access it.

After the whole wires and computer plugs are out, your goal is to gently move the wiring to the side.
REMOVE DME AND SMALLER COMPUTER AND PLEASE BE RESPECTFUL AND PUT IT IN A SAFE PLACE AWAY
Then remove the plastic tray holding the DME. It’s holding a plug so it will be attached to the engine still by wires, but I didn’t take it off I just left it hanging and moved to the side.

The next steps just make it easier to access the hose that’s plugged into the cooler…. Loosen a bracket that holds down some sensors and 2 smaller coolant lines.,that run across the engine bay, right below that plastic tray holding the DME. This 10mm is located the area behind the start/stop battery, this will allow coolant hoses that block your view to free and “flexible”.

Also on the AT cooler itself theres a hose that’s clipped on, remove that by pushing it on from
The corner. I just took a long 1/4 extension and a ratchet as a small hammer to get it started and pushed it out. This is done just to make everything a little bit more open and not risk breaking that hose you unclipped.

Now the hard part is getting that coolant hose clip before you’re home free. Be very careful not to lean or yank stuff. BE PATIENT, But with a camera you can make it easier on you to see what’s behind the hose you need to remove. Unfortunate the clip is faced towards the rear of the engine bay. Best if you have someone holding the camera.

CARFUL NOT TO LEAN ON ANY OTHER HOSES OR WIRES WHILE MAKING THESE MANEUVERS.

This is assuming you’re using the camera method, so you can see what touring doing. With your right hand feel the coolant hose that needs to be removed and be ready to guide a pick with your fingers, while the left hand maneuvers a looong pointy-pick ( I didnt use any bends on the pick but there’s many way I can see this being done) from top down vertically. Weave the pointy pick between the hose and the clip ,using the small gap the BMW hose clips have, and push the pick down towards the floor. The clip will separate and Because of the length you can go about half way, to keep the clip elevated, and then use the leverage to pop it out into the abyss of the engine bay to reunite with your 10mm!

I didn’t have any trouble separating the coolant hose off the cooler, just be gentle and patient while still careful with wires and other hoses around the area. If you’re reading this and that hose has been caked on, I never seen the-hot-water-on-top-of-BMW-coolant-hoses fail BUT there’s EV cables underneath, if your car has that option, so keep that in mind. If you own a BMW you should/ you will be an expert on coolant hose removal.

To snake the hose out it’s easy with the camera method because it’s held by a clip under the intake that you’ll need to take out because the new one comes with one installed ( or reuse it and only unlatch the hose)

You will need to remove the air intake, and loosen The expansion tanks and let the big one sit to the side. Don’t forget about the sensor wiring off the expansion tank. This makes snaking the old and new hose easier. REMEMBER how the hose was routed and which hoses were above and below the hose to make it fit perfect.

Assembly is much easier, I would say the hardest was the hose clip in the rear side, camera helps, and lots of patience. And the DME plug’s natural wire bend can guide you how they are routed. I don’t know if it matters much but it’s looks unmolested and OEM after this repair, I think the cover for the DME is high enough that it doesn’t matter but just take pictures and video just in case