It's not easy. There are plenty of instructions on the web, and some with pictures. The crosses are critical and the termination knot is not that difficult, just takes practice. Armor, like Swords, requires expert craftsman to take care of. Silk, be it Odoshi or Tsuka Ito, rots and falls off. Many of us would discourage anyone from attempting to repair the Ito on a valuable sword, it would be recommended it be sent to a professional. Same with quality armor, it's best in the hands of trained craft-persons. But when they are not high-end items, people are less critical of home repairs.
I started collecting low end pieces initially, and as my knowledge and experience increased, I started to buy and collect higher end pieces. I was taught to lace armor by Thatcher and Bottomly and spent years practicing and taking criticism from Thatcher when my work was slack. He was not being mean, but pushing to ensure quality was the output.
The late Anthony Bryant has/had a site that walked you through lacing armor and the different styles.
I will point out, one should NEVER drill the holes larger on the plates, that usually means you have the wrong size odoshi. Never use anything that will chip or destroy the urushi, once that happens, moisture will creep in and start the red death (rust), and cause the urushi to lift.
There is a "face" to odoshi and set ways in working with it. You'll get there, if you wish, but just study how lacing on good armor looks and how it rests, and this will inform your next job. Once you've studied a lot of quality lacing, you begin to spot work undertaken by less skilled craftsmen.