The only tool you will need is something to push the metal clip off the hose so all the old nozzle parts can be removed from the hose. Any fine pointed tool will work such as a screwdriver but my favorite tool for this is a pair of needle nose pliers. I use the two points of the pliers to push against both open ends of the metal clip and it slides right off. Sometimes if you are pushing against the clip on just one side with a screwdriver the clip just spins and doesn’t come off easily. I take the nozzle and on the bottom section where the hose attaches there is a plastic nut that secures the hose to the sprayer nozzle.
This nut usually unscrews by hand and I then put the sprayer aside after making sure no parts remain in side the nozzle. I lay the old parts on the counter in order of how they come off for comparison to the replacement nozzle taking the parts off the hose and putting them in order. When replacing a nozzle it is important that you replace all the parts as there may be slight differences between manufacturers but the end of the hose is pretty much universal. After taking off all the parts including the clip and the nut keeping them in order take the new sprayer apart again laying out the parts in order of assembly. The new nozzle will have all the parts put together in the correct order of assembly with the exception the clip, which will usually be loose in the bag.
Make sure that you keep both the new and old clips handy, they often fly when trying to put the clip on and more than once the old clip has saved me. Start putting the new parts on the hose and determine where in the order of assembly the clip goes on finish stacking the parts and screw the nut onto the sprayer nozzle. If the parts are properly assembled the sprayer nozzle will rotate on the hose and the hose will not move in and out of the nozzle. Turn on the faucet and test the hose connection for leaks. While the water is running both turn the hose and try pulling the hose in and out of the sprayer. If the connection leaks you need to pull it apart and try a different clip location. If it doesn’t leak congratulations you have completed the job and are now an expert.