#1844

usermod -u <NEWUID> <LOGIN>    
groupmod -g <NEWGID> <GROUP>
find / -user <OLDUID> -exec chown -h <NEWUID> {} \;
find / -group <OLDGID> -exec chgrp -h <NEWGID> {} \;
usermod -g <NEWGID> <LOGIN>

groupmod -g

Source: Linux: Changing UIDs and GIDs for a user by Stuart Colville

Permission, unix, User

Mount an FTP host as a filesystem using CurlFtpFS How To Set Up a Firewall Using FirewallD on CentOS 7 | DigitalOcean