HPI nitro truggy differential fluid change questions

[76Vandura4x4]

So I’m finally in the home stretch of my nitro HPI 4wd truggy rebuild, the last thing I need to do is change the diff oil. I have never done a fluid exchange nor have a I owned an awd truck before this one. Where do I start with this particular model and what do I need to remove on the diffs to get the oil in there. I already have read up on the best weights to use and I have 3k, 5k and 6k, I just ordered an new bearing kit from Fast Eddy’s as well. Picture of my rig for reference.

 

[HPI_lover]

Ah, good ol hpi
My favorite as my profile suggests
I have not seen a set up like yours before but it looks really nice and you put a lot of time into it
Awd especially being nitro it would be best to start on either the front or rear diffs as they're a little bit simpler to get to then the center one, the center in my experience is tricky to get to but my center in my hpi was a touring nitro and a lot more compact then what your set up looks like
Curious though and I might be able to provide more help based on it but is it a aftermarket chassis and also are you running stock or aftermarket diffs?
This would be helpful info and I might be able to provide more help depending on what your answer is
Otherwise looking good and I'm glad to see someone else restoring hpi's to their former glory