Link your Rockstar Social Club account to your Google account. After this is completed through the in-game steam browser, upload your video through the Rockstar Editor (via pause menu) to Youtube/Rockstar Social Club. Achievement will unlock after this is complete. Errors that limit your ability to link the accounts can usually be fixed by closing all "overlay type" applications open on your computer. These include (but are not limited to;) MSI Dragon Gaming Center, MSI SCM, Xsplit Broadcaster/Gamecaster, Nvidia Shadowplay/Share/Streaming, etc.