Clean-up with several iceweasel/firefox installed

[commentsabout at riseup.net]

Hello,

A couple of months ago, I asked on this list how to migrate from 
Iceweasel to Firefox (thread: Migrate from Iceweasel to Firefox on 
Debian Jessie). I received valuable help from "Fran Glais" off-list and 
managed to migrate.

Today, I'm facing another problem. It looks my system is polluted with 
several firefox/iceweasel versions.

Screenshot: https://s9.postimg.org/b29e9frsf/noname.jpg

CLI:

noname at pc ~ ls -la /usr/bin | grep firefox
-rwxr-xr-x 1 root   root     113 Aug  3 02:28 firefox*
lrwxrwxrwx 1 root   root      30 Aug  3 02:36 firefox-esr -> 
../lib/firefox-esr/firefox-esr*
lrwxrwxrwx 1 root   root      22 Aug  3 05:07 firefox.real -> 
../lib/firefox/firefox*
lrwxrwxrwx 1 root   root      30 Aug  3 02:36 iceweasel -> 
../lib/firefox-esr/firefox-esr*

I would like to use the latest (release) version, not the ESR one.

How do I remove older versions/aliases and set the latest release as 
default?

Thank you in advance for your help,

C.A.