Welcome to the forum, see you been here for a yr and first post.
Not a big deal to adjust, little scarry at first maybe. just have the
proper tools, like the bent 14mm and the feeler gauges. make a drawing
of the valves or print Diesel giants. follow his pictorials and you will do
fine.
Don`t get the intake and exhaust mixed up, easy to do

.
Just start with the first one and move down the line. then recheck ea
one after you are done with the feeler gauge.
Charlie

Merry Christmas