If you're not familiar with DFSORT and DFSORT's ICETOOL, I'd suggest reading through "z/OS DFSORT: Getting Started". It's an excellent tutorial, with lots of examples, that will show you how to use DFSORT, DFSORT's ICETOOL and DFSORT Symbols. You can access it online, along with all of the other DFSORT books, from:
You can try giving BNDS option in front of your first row and set the BNDS pointer '<' to the specific column want to delete. Then shift that many columns to left using ((8 (in your case) on first record and ((8 at the last record. Once that particular column is deleted, set back the BNDS pointer to the first column.
Try this out..might work faster for less number of records, where a file can open in edit mode..