[Swiftness~]

Hi guys have a few questions so Im nearing 55k miles and plan on changing fluids that I havent done yet for my 35i Xdrive. I did a search and found out for the front diff I would need two bottles of #83222413511 fluid and two #33117525064 drain/fill plugs.

For my transfer case I would need just one bottle of #83222409710 and just one #33117525064 fill plug (guessing plugs are same as diff)

Would like to know the fill amount as nothing is mentioned on newtis or am I reading it wrong.. but am I suppose to empty out the bottles while filling on both diff and tc?

Also on another thread it is mentioned some have used ista after doing TC fluid change...is that a must?
Im under bmw extended warranty so I just want to br sure. Thanks in advance!