The temperatures look about right; however, before you start try to achieve the 1C/sec dynamic over the area of the chip you are about to rework while maintaining accuracy, i.e., you need to be at 239C, then heat up 1C in one sec then stop at 240C. You will need a big heater with thermal mass much larger than your board (and preferably two - one of each side of the board), with good temperature control. Re-working large BGA packages is non-trivial, expect to fail the first time you attempt this so don't practice with expensive chips.
Pre-heating to 190 can be done slower, almost any rate will do as long as you don't stay anywhere close to this temperature for more than couple of minutes.
Also think about inspecting your work after reflow - you'll need access to an X-ray machine.