Digital BW, The Print

Hello Group,

I rescaled (By 180%) my image(s) and want to now reduce the canvus
size. But when I do that ,of course, part of the image now is NOT on
the new page.
Is there a *Centering* stage that can be performed *BEFORE* resizing
the canvus so everything will fall into place. I have 5 plates that
must be printed at the new size in the correct places, with different 
colors on Alps.

Thanx,please, excuse the cross-post.

Art Griffin