Creating a new sector in IMPLAN

Is there an online tutorial for creating a new sector in IMPLAN? Basically, I am splitting the fruit sector into an apple sector and an all-other fruit sector, customized with primary data collected. My previous approach was to use an 'empty' sector in the study region (e.g., in my case tobacco). However, while there is no tobacco industry in my study region, there is purchases of tobacco commodity from other industries (e.g., cigarette mfg), presumably all nonlocal. I've had some issues on changing institutional demands and RPCs, but think I've figured it out. Is there any way to, say, create a totally new (537th) sector to do the same exercise; i.e., leave tobacco alone and create one more sector?