This is the main riff that's played on guitar through-out this song.
[ Tab from: https://www.guitartabs.cc/tabs/j/judas_priest/eulogy_tab_ver_2.html ]
e--------------------------------------------------------------------|
b--------------------------------------------------------------------|
g--------------------------------------------------------------------|
d-----------8-----8------8-6------------8-----8----------------------|
a--6----6------6------6---------6----6-----6--------9-----9----------|
E------------------------------------------------7-----7-------------|
Repeat this through the whole song. It's rather simple.