That is basically the correct library. However it seems to have changed (and unfortunately the author seems to have forgotten to update some comments about the version in several files).
I downloaded the latest version using the library manager in the IDE and indeed found that IRremoteInt.h is no longer that big. Reading though the new IRremoteInt.h, it contains below lines (lines 110 and 111)
// All board specific stuff has been moved to its own file, included here.
#include "boarddefs.h"
If yours does as well, you need to look in boarddefs.h
There you will find (lines 194 and 195)
//#define IR_USE_TIMER1 // tx = pin 9
#define IR_USE_TIMER2 // tx = pin 3
I haven't tested, leave that up to you.