I Really Wanna Learn arm grinds but i cant find ANY tutorials anywhere.
so can you guys just kinda explain how to do it.
Look on this website. The video is called basic grinds.
If you can land a trapeze you can do an arm grind, just slide the yo-yo up the string towards your throwhand and let the spin of the yo-yo cause the yo-yo to pull itself onto your hand. Once it gets to your wrist pull the yo-yo back to the string (back into a trapeze) and then catch it.
Practice this a few times until you can do it consistently (just to get a feel of how much the yo-yo can spin on your hand before it runs out of spin, how to balance the yo-yo correctly, etc). With time you’ll have a better sense of balance and all you’ll have to do is give the yo-yo more slack and let it travel further up your arm.
Once you’re good at grinding on your throwhand arm, you should move up to grinding on your freehand arm. To do this throw a breakaway, move your freehand as if you’re going to do a trapeze but allow the string and yo-yo to pass above your hand. With your freehand arm straight out and underneath the yo-yo and string try and set the yo-yo down on your index finger, the yo-yo will naturally pull itself up your arm.
If you’ve practiced on your throwhand arm quite a bit you’ll already know how to balance the yo-yo to get a good grind up your freehand arm. It all takes practice, but it’s an amazing trick and a great crowd pleaser! Good luck!
Let me know if you need clarification 
Trapeze
Pop onto arm
Grind off
(Lol better explanation in vid)