KitKat won't fit on the stock partition. You need to enlarge it with BigPart.
Go to the development sub-forum. Follow the directions in the BigPart resource center, then install your choice of 4.2.2 ROMs.
BigPart has been around long enough that there are dozens of pages of comments. I'd suggest starting at Page 1 and reading through them to get a clearer idea of the process.