The steps are easy:
1 - Have the two ends of the lengths to be joined, laid side-by-side for just over a hand's breadth
2 - Make a loop, with the two lengths leading away from the rod over the top
3 - Put your finger up through the loop from underneath
4- Make two anti-clockwise turns in the loop
4 - Pull the two lengths leading away from the rod through the loop
5 - Check that you have the two lengths all the way through (don't leave the short end behind)
6 - Slowly draw the knot a little tighter until you have a figure-of-eight shape in the knot
7 - Moisten the knot with spit
8 - Draw it tight, holding it tight for a couple of seconds.
9 - Suck the spare spit off the knot
10 - Trim away the waste ends
Here are the 10 steps in a word-free video!
Please do give this a try and let me know how you fare with it. You won't regret learning how to tie this excellent knot.