hg backout [OPTION]... [-r] REV

reverse effect of earlier changeset

    Prepare a new changeset with the effect of REV undone in the current
    working directory.

    If REV is the parent of the working directory, then this new changeset is
    committed automatically. Otherwise, hg needs to merge the changes and the
    merged result is left uncommitted.

    Note:
      backout cannot be used to fix either an unwanted or incorrect merge.

    See "hg help dates" for a list of formats valid for -d/--date.

    Returns 0 on success.

options:

    --merge               merge with old dirstate parent after backout
 -r --rev REV             revision to backout
 -t --tool VALUE          specify merge tool
 -I --include PATTERN [+] include names matching the given patterns
 -X --exclude PATTERN [+] exclude names matching the given patterns
 -m --message TEXT        use text as commit message
 -l --logfile FILE        read commit message from file
 -d --date DATE           record the specified date as commit date
 -u --user USER           record the specified user as committer

[+] marked option can be specified multiple times

use "hg -v help backout" to show more info