There are shellscripts for changing ower of files or directories..

find_gid_and_chown_group.sh

#/bin/bash
# Finds the object with the specified group ID and changes the owning group.
#   _gid : Group ID that remains unchanged
#   _grp : Group name you want to change
find_gid_and_chown_group() {
    _gid=${1}
    _grp=${2}

    _buf_ifs=${IFS}
    IFS=

    find / -gid ${_gid} -print | \
    while read _path
    do
        if [ -d ${_path} -o -f ${_path} ]; then
            # Change the ownership group of directories and files
            echo "Change ${_path}"
            chown .${_grp} ${_path}
        elif [ -h ${_path} ]; then
            # Change the owning group of the symbolic link itself
            echo "Change ${_path}"
            chown -h .${_grp} ${_path}
        else
            echo "No Change ${_path}"
        fi
    done

    IFS=${_buf_ifs}
}

find_gid_and_chown_group $1 $2

find_uid_and_chown_user.sh

#/bin/bash
# Finds the object with the specified user ID and changes the owning user.
#   _uid : User ID that remains unchanged
#   _usr : Username you want to change

find_uid_and_chown_user() {
    _uid=${1}
    _usr=${2}

    _buf_ifs=${IFS}
    IFS=

    find / -uid ${_uid} -print | \
    while read _path
    do
        if [ -d ${_path} -o -f ${_path} ]; then
            # Change the owner user of directories and files
            echo "Change ${_path}"
            chown ${_usr} ${_path}
        elif [ -h ${_path} ]; then
            # Change the owning user of the symbolic link itself
            echo "Change ${_path}"
            chown -h ${_usr} ${_path}
        else
            echo "No Change ${_path}"
        fi
    done

    IFS=${_buf_ifs}
}

find_uid_and_chown_user $1 $2