make the spring install an easy one!!!!! I used my 10pound slide hammer, one hit and it's done!!!!!!!!! I used a few wood blocks, duct tape and cloth towels, wood blocks to support the mirrors, duct tape to hold mirror in place and the towels to protect the surface, by myself it took me about 5 to 5. 5 hours to complete the change over and install them on my truck, I tow a 26 foot inclosed car trailer, this is the best upgrade, just hit the switch and adjust on the fly!!!!!