ULTRAEDIT and other powerful editors will allow you to open such large files as well as replace text. Maybe a simple program to replace such text with a space or line feed could also be handy.
It is possible that only a section of the model is generating the problem so a run of just parts of the model may isolate the location. Once isolated you may want to then make changes to model geometry to reduce the number of occurrences of the error messages.
Anthony Kuch
XP Software Inc.
anthony@xpsoftware.com