regulation Valvesan terrano td27 year 1993

A cordial greeting everyone, my consultation is the Sigante. I have a Nissan Terrano TD27, 4x4, Turbo, year 1993. My jewel, the issue is that I always repair it. Well, I change cylinder head packaging, water pump and other things, the problem is that I don't know how to regulate waves, I would like Saver if there is algien that indicates in detail how this is done. I will thank you for your help.