A slightly more manual way is to tap into the list of actions, and then chose the «Send a text to...» option. (androidcentral.com)
So if you haven't received the official invitation just yet, you do it the usual manual way by hitting menu > settings > about tablet and check for updates. (goodereader.com)
Along with the automatic ways, there are also available manual ways through which you can update your Kindle device. (amazonkindlesupport.xyz)