That's a pretty basic task for any Android user. In fact, if you can't do that, then you probably have no business whatsoever installing a customer ROM.
Think of it as a basic intelligence test - you want to change your car's air filter - first step is to pop open the bonnet. If you can't do that, then you probably want to seriously consider, gee, should I just get a mechanic to do this?
This isn't like some test to pass before changing your oil. It's like requiring Ford's permission to install some fuzzy dice or a custom seat cover.
This is wrong.
Allowing this is built in to Android and it's a user togglable setting.
Verizon explicitly mentions sideloading and how to enable it:
http://mobile.vzw.com/LocationAgent
For Android devices, please confirm the device's Location Services
setting GPS and Verizon Location Services (if present) are set to
on and the device's Settings > Security > Unknown sources is checked.
http://cache.vzw.com/multimedia/mim/mot_droid_razr_hd/razrHD...
PDF Page 15: To let your smartphone install apps that are not from
Google Play, tap Apps >Settings >Security & Screen Lock
and check Unknown sources
Ditto AT&T:https://www.wireless.att.com/businesscenter/en_US/pdf/att-to... PDF Page 3:
In order to install these apps, you must ensure the 'Unknown Sources'
box is checked [...] Follow the instructions on your phone to enable
this feature and continue with AT&T Toggle installation.
http://www.att.com/esupport/article.jsp?sid=KB410684&cv=820 Before you begin, you'll need to set your Android smartphone
to allow downloads from non-Market sources by selecting Unknown sources
in the Settings menu on your device.
Ditto Sprint:http://eguides.sprint.com/support/eguides/htcone/content/htc...
Go to Settings > Security, and then select the Unknown sources
option to allow the download and installation of the tool
through your Web browser.
http://eguides.sprint.com/support/eguides/sprintvital/conten... If you want to install apps from sources other than the Google
Play Store app, you must allow the installation of apps from
unknown sources first.I've honestly never seen it before, and I'm curious what manufacturer would actually do this nowadays.
[1] http://www.sleetherz.com/2011/05/att-users-now-you-can-insta...
There is a basic freedom lost when you allow yourself (the entire software market) to be subject to arbitrary corporate control especially when there is inadequate competition. It's clear that the terms are there only to serve the corporate interests and can change at any time if corporate interests change (hello G+ & YouTube)
Google doesn't want people to hold it liable for potential bricking of devices and took it off its store. What's the issue here?