Harry Bloomfield wrote

This is a copy of the entire instruction manual for a carcam, just
as supplied by the manufacturer. 8x pages of instruction, all of
the pages on one side of an A4 sheet in a landscape of 4 x 2 grid.
It is just about readable with decent lens in its original form, but...

I have done an high res scan of the page saved as a jpg and I should
like to be able to print it out as 8 separate, enlarged A4 pages, but
I am not experienced in graphics programs - what it the easiest
way to do it? A beginners simple step by step guide please.

Anything like irfanview can crop the original into 8 separate
jpgs, one for each page and you are free to print those.

Even paint does it fine if you use Win.