Volume ID is always saved at offset 0x8028 as 32 bytes in format ASCII string.
This script is modifying from this position.
$ genisoimage -V IR1_SSS_X64FREV_EN-US_DV5 -o test.iso *
$ isoinfo -d -i test.iso | grep 'Volume id:'
Volume id: IR1_SSS_X64FREV_EN-US_DV5
$ ./changevolumeid.pl test.iso IR2_SSS_X64FREV_EN-US_DV5
$ isoinfo -d -i test.iso | grep 'Volume id:'
IR2_SSS_X64FREV_EN-US_DV5