Filing L1-A for international manager role

Hello Experts,

I am currently working in United states for over 2.5 years and with current employer since past 5 years now. I have total 10 years of experience which also includes considerable resource management in my current as well as previous experience.

Also, I have been working in a specialized stream for this company and am an inventor of an IP in terms of patent pending solution. I am currently on L1B with my specialized knowledge but my role is evolving and I am now handling cross function teams across locations (US, 2 locations in India). My questions are,

My current L1B is expiring, How easy/difficult is to file for an L1A extension considering my situation? Can anyone guide me on most important aspect which must be considered?Can this change of status be done from US itself? or does it require a new petition to be filed from India?Regards