usage: copy jar file into folder that contains coverdb{X}.db files
type:
java -jar abcoverpacker.jar -u coversU.db coversU_export
to export all covers into coversU_export folder
edit the covers in graphics tool like gimp or replace covers using same file name (PNG 226x226)
type:
java -jar abcoverpacker.jar -p coversU.db coversU_export
to put back all the updated files back to database - the database now has all covers reloaded
you can do the same on J or P cover databases.