@Abigai I would print out the pattern, physically or digitally to a format you can edit it in. Then I would draw a straight line down where I would want to cut off the strings. So say I wanted to do 14 strings (roughly half), I would count 14 strings out (3rd B-colored string from the left) and draw a straight line down in between the 14th string and the 15th string. You would make the bracelet as usual but you don't make the knot that the line intersects nor anything to the right of that knot. Instead, the string that would normally make that knot would just be left out to the side for that row. Sorry if that was confusing. Hope this helps!
@CJullyan well it's a really thick bracelet and BIGG. you want to have it really long. I don't measure exactly but just eyeball it and make it really big