Gus, the front bearings definitely will need to be lubed, and yes this should be done by someone that has the equipment and the experience. The front preload is set by the spacer in each of the front hub assy's loose it and it will eat bearings forever, swap it with the other side and you may never get it right again. I bought a tool called the "Hub Shark" it worked great. A hydraulic press is the shop standard, if you have access to one and know how to use it, it will make your life much easier. Under no circumstance should you be hammering anything (no hammer mechanics allowed). Buy all the seals and bearings for the front once it is apart you should replace everything the same is true for the back. The rears are much easier, pull the nut and everything comes apart in your lap. You will need to press in new races for the tapered bearings (everyone always skips this step) but that is pretty standard.