Command run:

bufralter.pl 1xBUFRSYNOP-ed4.bufr \
--data 004004=-1+ --data 004005=50 --data 012101=missing \
--update_number -1 --bufr_edition 3 --centre 88 \
--master_table_version 11 --local_table_version 0 \
--outfile altered.bufr

Decoded content before running bufralter.pl (decoded by running buffread.pl on 1xBUFRSYNOP-ed4.bufr)

Decoded content after running bufralter.pl (decoded by running bufrread.pl on altered.bufr)