HP plotter

[Jimmy D]

I have an old HP 7596A that I still use for my work. There are a few things that I'm curious as to whether they can be changed, but I'll ask one question at a time.

The plot limit on this model (E size?) is 36 inches wide x 48 inches long. I'm interested in doing a longer plot, say 5 or 6 feet. I have some manuals I bought on a CD, I've been snooping around on them. 

The hard clip is the physical limits of the plotter, the soft clip is the software limits of the plot. In the pocket guide, there is a place where it says:
PS,  page size
Use: Changes the size of the hard clip limits
Syntax: PS length(,width); or PS;

Could I hire a computer expert to change the length setting? Or even do it myself? Maybe a long shot, considering computers are not the subject I've spent much of the last 20 years studying. Any technical answers should be s-l-o-w-e-d down from your usual warp speed to biplane or maybe hang glider :)
Thanks for any help.