1. Goto youtube.com desktop page
2. Copy the page address of any video u want
3. Goto savevideo.me
4. Paste link there and click continue button
5. Click on the desired resolution and format
6. Download will start but file name will be ''UNTITLED''
7. Rename ''UNTITLED'' to
''videoname.flv'' if it is a flv file or ''videoname.mp4'' if it is mp4 file.

And you are done!!

Supported resolutions are -
1080p, 720p, 480p, 360p, 320p, 240p
Supported formats are -
Mp4 HD, mp4, flv, webM.