From: snoze pa (snoze.pa_at_gmail.com)
Date: Wed Jul 25 2007 - 14:42:05 CDT

set sel [atomselect top all]
$sel set resid [$sel get residue]
$sel writepdb renumbered.pdb

when i am using above then it is rename the 20A to 20, 20B to 20 and so
on.,.. but nothing working!