How to install Hardiebacker cement board for a shower or bathroom

How to install Hardiebacker cement board for a shower or bathroom
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[model-man]

I'm new to this, the wall behind our tile gave way and was waterlogged and molded up to about eight inches.I bought hardie board but its thin.do I need to put that gray cement board back up then hardie board then tile?

[KooperSalmo]

WATCH ALL MY SHOWER BUILD VIDEOS JUST SEARCH - how to build a shower by kooper salmo

[Sharper]

What's with lights in the shower don't seem like a good idea.