They are easy to install. Keep in mind use at least one spacer under the top crown and then as many on top that you want. (or underneath if you want to lift the front). The only tool I use is an allen key. As for oil height and spring weight I would check this in relation to your weight the very first thing. Marzocchi's are notoriously undersprung and under oiled. Check the website for recommendations and go by it. I would be surprised if your fork had the proper oil height in it
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As for spare oil, my dc is a loaner so I have no idea if it comes with more oil.