Dumb question but where do you get grind plates?
danscomp
.com
Some people make their own out of sheet metal, otherwise you can just take the pins out of your pedals, or wear down one side.
If you use something like the original UDC wellgo’s, or DMR platform pedals, then you’ll need a special plate to slide on since they don’t really have enough metal to hold up to proper grinding, and you’ll break the pedal after a while. If you use something more like Jimmy C’s though you can get away with just taking out the pins from one side of the pedal, and after a while the pedal just ends up a bit worn and flat on that side. Its personal preference, I’ve always done grinds with a plate, but I might upgrade to Jimmy C’s soon and just remove the pins.
Note: If you want to take all the pins out of pedals like the Onza stock platforms, where they aren’t all unscrewable, Kington99 managed to get his other pins out by grabbing the non-screwable ones in a Vice (Vise to Americans I think) and using that to pull them out. They’re as removable as normal pins but just with a little more effort.
Loose.
u cant pull pins out of all pedals, can u, or do u have to have a certain type?
If the pins are cast into the pedal body you can just file them down, but pedals like the onza where they are seperate from the main body but no unscrewable, you just need to pull them out.
Loose.
your best off just to find some scrap sheet metal and make em yoursself
don’t laugh, wat does a grind plate look like?
well it kinda looks like a PLATE!!. actually the ones ive seen ar e about a quarter inch thick and the size of the pedal.
a grind plate can look different, depending on what material it is made of!
the danscomp plate is made of a fiberglass looking material (called something else) but ones u make with metal sheets, look like metal 
they r just a little plate that fits on one side of a pedal, and is flat!!