You'll find a Factory Service Manual on the forum site. Download it, and read through the first 2-3 chapters. You'll find the cam chain adjustment process in there.
Good luck, and let us know how it goes.
Luke M
Used to have a 1979 CB750L, sold it as a parts bike, now riding a slightly modified 1984 VT700C. Network/Field Engineer. Central OH, USA, Earth, Sol System, Milky Way Galaxy, Universe.