How to change title dynamically in a pie chart (jQuery/JS/ Highcharts)

This question is on Highcharts, so if anyone has any idea please, do help.

What I want to do is describe what area of the circlePie chart the cursor is hovering over. In that description, would be the name of the area of the circlePie and the amount of num tons(eg. 5.5t).

The second part of title is the subtitle or total, i just need to know how to isolate the different sums found and how to add them all to make the total.

No takers; it is as I feared