There's also CR2Builder, a specialized Poser file editor. While EditPad is very good for this sort of thing, sometimes your system memory will cause sluggish behavior if the file is too large (files containing large numbers of morph target deltas). CR2Builder gets around this by not loading any morph target deltas into the system memory. It replaces them perfectly when re-saving the file, so no worries there.

However, CR2Builder's interface may seem intimidating at first glance, so I would recommend trying EditPad first.