DIY for front air struts

[LeMansX5]

We have threads on this topic here and there but no proper DIY in "How To's" section. I am doing mine and taking pics and will do a proper DIY in Articles section

I am replacing the passenger side air strut with Arnott's rebuilt air strut. I removed the fuses 79 and 87. I removed the wheel.

I check the air bag, feels no air inside(as against driver side which is tight), so I assume this is already done. I start removing the end link nut, and all of a sudden I hear hissing and touch the airbag and it feels tight and filled with air ???? Shouldn't the removed fuses stop the filing of air?

Arnott's (inadequate)instructions say remove yellow cable from "Air system manifold" in underbody. Where is that?

Shall I just disconnect the battery?