HAJM

I am using Cura 14.13.1 and want to change the infill setting for part of my model, but I cannot find how to do this., though I was able to do it on a previous version of Cura. I have seen a video demonstrating this feature, but it used an earlier version which had different icons for altering the model. Is this feature still available in 14.13.1 and, if so, how do I do it.