I just went through the same thing today installing my ebay one. It's really easy to install but trying to stabalize the coolant bottle is a b****. You really don't need to take off the bumper. But for me I did take off the bumper so I can install rubber door molding around the hole where the piping goes through, and added rubber weather strips to the metal area where the filter is. Basically I did that so I wouldn't have any metal to metal contact. Which I'm glad because I have no rattling sounds. But I'm like a pro on removing my bumper, I can do it in less than 5 minutes.