This guide is great, but if you just want to install Transmission there is an easier way whiteout using SSH:
Open your WD MyCloud from a browser (tested on Chrome, others will fail because security settings)
Hit enter, browse Applications and you will find a fully functional install applications menú.
Download application from @Fox_exe website anionix.ru and install manually using the previous menu.
(Note: to uninstall the applications you will have to follow the same instructions to enable the buttons)
Also you can install WDMyCloud_WDCrack_1.0.bin and have the same functionality without enabling SSH and running scripts
Tip: you can even create a bookmark and set it's destination URL to the code quoted before to enable with a click this function (or other functions from define.js).