Welcome to FT!
Looking at the properly-formatted version of the fare rules, you can see that the "CHANGES NOT PERMITTED" is listed in the "CHANGES" sub-section. "TICKET MAY BE UPGRADED" is listed under "CANCELLATIONS".
So yes, you can
cancel the ticket and apply its value (less the $150 USD penalty) to another ticket (of the specified fare type). This is
not considered a change, and the fact that changes are not permitted is irrelevant.
[KVS Availability Tool 2.8.5/Platinum - DotRes: SFO-BXN/TK/KKWAP1M/1290 USD]
Code:
PENALTIES:
CANCELLATIONS
BEFORE DEPARTURE
TICKET IS NON-REFUNDABLE.
NOTE - TEXT BELOW NOT VALIDATED FOR AUTOPRICING.
TICKET MAY BE UPGRADED TO TAFP RULE 4605 H-AP3M
TYPE FARE PROVIDED THE FARE DIFFERENCE IS PAID
PLUS A CHARGE OF USD 150.00.
----
PENALTY DOES NOT APPLY TO INFANTS UNDER 2 YEARS
OF AGE NOT OCCUPYING A SEAT.
AFTER DEPARTURE
TICKET IS NON-REFUNDABLE.
CHANGES
BEFORE DEPARTURE
CHANGES NOT PERMITTED.
NOTE - TEXT BELOW NOT VALIDATED FOR AUTOPRICING.
CHANGES ARE PERMITTED TO DATE OR ROUTING OF
DOMESTIC TR SEGMENTS WITHOUT PENALTY. IF THE
CHANGE CREATES A CHARGED STOPOVER OR INCREASES THE
FARE-ONLY THE DIFFERENCE MUST BE PAID.
AFTER DEPARTURE
CHARGE USD 150.00.
NOTE - TEXT BELOW NOT VALIDATED FOR AUTOPRICING.
PENALTY DOES NOT APPLY TO INFANTS UNDER 2 YEARS
OF AGE NOT OCCUPYING A SEAT.
------
CHANGES ARE PERMITTED TO DATE OR ROUTING OF
DOMESTIC TR/US SEGMENTS WITHOUT PENALTY. IF THE
CHANGE CREATES A CHARGED STOPOVER OR INCREASES THE
FARE-ONLY THE DIFFERENCE MUST BE PAID.