There are a few options to change the pin numbers. You can use Layout - renumber pins and pick the optins required in the GUI but these options are based on JEDEC_TYPE standards so the renumbering options required might not be suitable. The next option is to delete the pins and add them back in, The Layout - Pins Options menu (fold out on the right side of the screen) allows full control of adding multiple pins in one go. You can also have full control of the Pin number and increment so you could add two rows of pins 1,3,5 etc first then 2,4,6 etc. Finally you can use File - Export - CSV Pin File, make the changes in Excel then delete the pins in the filename.dra and use File - Import - CSV Pin file and import the modifred version.
You are probably better off using the PCB Design forum for this type of question.