22.10 Update

Seems something changed that stopped Apt from fully uninstalling all Snaps, causing the rest of the uninstallation process to fail. This new version will uninstall each snap directly through Snapd before removing snap itself through apt now, making sure everything is fully removed.
22.04 LTS should be able to run this same version of the script just the same.

Separate script to install to /opt instead of a user's .local directory is provided until I can get some proper UI coded to do it in one file. Bare in mind that alternate script will not work for multi-user systems.

Opt install location and Legacy Icons

New variant added that installs to the /opt folder instead of .local.
Makes it much faster to access the Firefox folder if you tend to make a lot of tweaks like me. This variant isn't made for multi user systems, as only the person who runs the script will have permissions to the folder, preventing other users from updating. Hence the multi user install script isn't included. Use the main script if your system has multiple user accounts on it.

Also included is a legacy icon folder, containing a version of the Firefox logo before Mozilla's controversial redesign. Rename it to replace the regular icons folder before installing if you want to use it.

First Update

Some trimming of the commands used should lead to some vaguely faster run times.
Curl is now no longer required, thanks to Silejonu.

Full Release - Kubuntu 22.04

First full release!
Minor adjustments made to the formatting of messages, and an additional script has been added to install Firefox for other accounts after running the main script. Bear in mind that you need to run said script on each account individually, as it installs to the user's home folder.
Don't forget to backup your Firefox profile!

I've repeatedly tested on multiple Kubuntu beta versions over the last two months, had one instance of other users testing on their systems, and have tried today's Release Candidate version for 22.04. Bear in mind that there haven't been any reports on any long-term effects of this script, so be cautious.
Any feedback or bug reports are, as always, very much appreciated.

Release Candidate - 22.04 Beta

Feedback implemented from Public Testing Release (Cheers!) including:
Moved the installation from /opt to ~/.local/share.
Fixed running Firefox through terminal commands.
Downloaded Firefox now uses American English by default.

Tested on the official Kubuntu 22.04 Beta release. Worked fine, but there are still no reports on the long-term effects of this script, so be cautious.

Hopefully this is the final version before release!

Public Testing Release

Time to destroy all the confidence I have in myself.

Tested on a Kubuntu 22.04 Live USB. Looking for feedback from others testing it on their own systems!
Any feedback at all is much appreciated. Any problems, unclear instructions in the script itself, or unintended effects of running it.

Initial Release

Initial release to test on Kubuntu 22.04 Beta Live USB.

Ideally, this will work exactly the same once 22.04 releases officially.