How to fix hyperblink on LED bulbs?

I just purchased some rear LED turn signals for my 2007 Nissan Sentra and installed them. After installing them they have they blink crazy fast.. I read that i need to install resistors, but i need to know what ohm & wattage of resistor i need to purchase and install, I should also be recieving some for my front turn signals pretty soon too, do i wire the resistor into all 4 lights or could i just wire it into the rear since it's easier to work with...