The page https://www.wwpdb.org/ftp/pdb-ftp-sites gives the addresses of interest. PDB has an FTP site downloadable via rsync and the latter has a dry run mode.
rsync --port=33444 -rlpt -v -z --dry-run --stats rsync.rcsb.org::ftp_data/structures/divided/pdb/
You get a bunch of folders names and the following:
Number of files: 182479
Number of files ...
Since this is not a correct PDB file, it can be interpreted differently by different PDB reading libraries. The most reliable way to change it would be to read it as plain text and change the chain ID to B in the lines that have segment ID LA0.
Note: Strings RA0 and LA0 start at column 73. Columns in the PDB format correspond to characters. This is not a ...