How to customize for mobile through responsive/ SDK

We are currently attempting to customize our mobile version but cannot seem to find out how to. Our mobile page is very misaligned and overlapping in places and so we need to alter the css to resolve.

The Issue: When I go to Studio> advanced > SDK , it tells me to reference "responsive_peak.css" 

Makes sense. so i visit the responsive base skin or responsive parent skin, the css is greyed out on both and both have a message at the top of the page saying "this skin cannot be edited". Basically its not allowing me to bootstrap or code anything into the responsive skin, no matter which subdirectory i click on. 

Went through our custom skin and, while i can of course edit that sass, there are no subdirectories that house or even seem relevant to the mobile version, sdk, or responsive skin.

Do you think our responsive is simply disabled? or am I missing something completely, looking in the wrong place, etc?  

Thank you in advance for your time and assistance!