I do the graphs using a program called Stata. I cut/paste the OPR output into a text file. It would be doable in Excel, too, but substantially harder, I think. (And I'm pretty slick with Excel). Dealing with rebuys isn't trivial. I think my way does the best job possible given the data that OPR provides.
I can't do complete history for high-volume players because OPR won't show all the tournaments. It only shows the last 3000, I think.
Here's an example (Clayton):