The easiest way to shorten the column is at the collapsing collar.
This how I shortened
a column out of a 72 Olds Delta 88 to fit a 75 Vega while stationed in
Germany eons ago.
doesn't require removing the whole column, just from where the shaft
clamps at the column housing adjacent to the fire wall and then undue
the rag joint at the gear box.  Heat the collar
area up, it uses a "plastic" to hold together, pull it apart when it
melts.  Install the gear box, measure the difference and then cut that
from the upper end of the lower piece, assemble in place and spot
wield in two places.  You want enough holding power to keep it from
coming apart, but you want the wields to snap if you get hit so the
column will collapse.  Its held like that for almost 30 years with no
problems.

Whitelightning