add user as another person with write permission on a folder - Ask Ubuntu

i'd add myself (already in webapps group) drwxrwxrwx permission whole folder recursively:

$ ls -l /var/lib/tomcat8/webapps total 67904 drwxrwxrwx 3 root    webapps     4096 oct  1 21:39 root drwxrwxrwx 8 tomcat8 tomcat8     4096 oct 11 18:01 appweb -rwxrwxrwx 1 tomcat8 tomcat8 69522664 oct 11 18:01 appweb.war 

i don't want remove permissions users have it.

other posts either come close helping me or don't understand, because i'm new.

it may know:

$ getent group webapps webapps:x:1002:tony,root,tomcat8