[need4speed]

Depending on how your tank is set up you need to remove the filler and/or the sending unit to gain access to the inside of the tank and then just pull the foam blocks out through the largest available opening. Of course depending on your car, if you do not have ready access to the top of the tank, then you will have to drop the tank first. The foam blocks will be larger than the hole that you need to pull it through but they are essentially just a sponge and can be compressed to pull it through. I highly recommend that you do this with an empty tank.