If you are using Premiere Pro CC with 7.2 update or later. You can go to Sequence>Sequence settings and change the frame rate of a sequence.
If you have the latest Premiere Pro CC then just go into Sequence Settings and change it.
Or, if you do not have that option, simply create a 25fps sequence, then select and copy everything from your 24fps sequence and paste it into the 25fps sequence.
But of this way, all editions and his timecodes will be scaled at new framerate???
Changing the frame rate of a sequence will not change the frame rate of the media.
If you're looking to deliver in a PAL country, I'd recommend just giving them a normal 24p DVD or Blu-ray. Pretty much all PAL players can handle NTSC disks