If you haven't already, double check that your thermostat is functioning correctly, as glow plug issues seem to snowball when the engine isn't reaching temp.
As far as the actual job of changing the module, its a bit of a PITA. I think it would have been quite a bit easier if I had remove the coolant pipe that comes off of the side of the block under the intake manifold. Its not strictly necessary, but it likely would have made life easier.
You absolutely have to remove the intake manifold. I reviewed the how-to here:
https://xoutpost.com/bmw-sav-forums/...-m57-pics.html
HOWEVER, I did not find that unplugging the swirl flap electrical connection was easier after the manifold was loose. Maybe with a helper it would work, but I found it difficult to balance the manifold in one hand and try to remove the plug with the other. I put the manifold back loosely on the head and found that I could unplug the connector with relative ease.
Once the manifold was out of the way (good chance to inspect it) I basically just unclipped some of the various vacuum, coolant and SCR hoses around the module just to make some more room. I removed the 2 nuts and took the module loose. I had a very hard time unplugging the larger connector, but I think that was because the the clips are barbed and I had too much tension on the connector. I eventually got it loose by prying with a screw driver and squeezing for all I was worth. The round connector came much easier.
Basically then you just work the module out from its little prison towards the back of the motor.
Snake the new module back in and bolt it down before plugging in the two connectors.
From there, assembly is the reverse of removal. Just make sure that the various electrical connectors for the manifold sensors are where they will be accessible once the manifold is dropped in place.
If you aren't sure when they were changed last, order both sets of manifold gaskets for re-assembly. I plan to take my manifold back off before long to replace them as they were not as nice as I hoped.