Go ahead and dilute and test again and see what you get. But, I will tell you that for the most part the booklet that comes with the kit is not good. Better off to just use methods learned here on the forum, although in this case dilution is the correct thing to do.

If you have a high CYA and are only going to be gone for 4 days, you should be in good shape. If you shock the pool before you leave, you will most likely come back to a pool that still has chlorine in it. That is one of the advantages of running a HiC2 (high chlorine/high CYA) pool. I would also take the pH higher than it is now before you leave, probably up to 7.7 or so.