I would like to change this to Bit 2.5 . I am currently using external interrupt 1. How would make the ammendment to make it work on bit 2.5 .
Not directly possible due to the limitations of the crossbar.
1) You can enable all peripherals which lay before #INT1 to shift it to P2.5, but then all ports from 0.0 to 2.4 are lost for the application. If you need these functions anyway, then it's no problem.
2) The other approach I can see to get it to P2.5 is to poll the input, either via a timer or directly in the application.
3) Connect the signal to the comparators rather than to P2.5. With comparator properly set up you can achieve additional external interrupts.

Regards,