Guys my vibrato sucks ass. Like sure I can do it nicely when its slow and wide but when it comes the really fast vibrato I absoloutly suck...which is bad because I cant get pinch harmonics to squeal enough, ect.

Can somebody give me an EXACT description of how pivit your hand, ect...with EVERY last detail. It seems no matter how many things I read and how many times I try Im just sill unsure on what to do.
Uhhh... Put your thumb on the top of your neck, put your finger on the string, and just rock your wrist. Alls you do is rock your wrist... If you havent dont it before it feels unnatural but do it over and over and itl come
It just feels like my thumb is stopping my wrist rock rocking or pivoting

Oh and Ive been doing it for about a year and a half now but I cant seem to go very fast
thats my problem