WHY LED BULB NOT NEED BALLAST:
Ballast is something that limits the current. In the case of a fluorescent tube, this is a separate inductor, in the tube fitting. This LED bulb requires no external components, everything it needs is contained within the assembly. It just plugs straight in to a standard bayonet cap fitting, in place of a filament lamp or CFL.
If you do not remove the ballast before install led bulbs, what will happen for the led bulbs:
1. The bulbs will flicker.
2. The buls can light on, but the bulb will broken soon.
Regarding how to remove the ballast:
Step 1 Ballast has a black and white wire on the input side(220V).It also has to red and two blue output wires. To bypass this ballast cut all 6 wires
Step 2 Then you can connect the two wires to the black wire.
Step 3 finally, connect the two blue wires to the white wire.