Being that you're outdoors let them use the last night and then chop in the am. Bring them into a dark, warm temp room, like 65-70 degrees, keep humidity low at least 50% or lower and then just check them regularly. If the outter leaves begin to crisp and the small buds pluck easily then its time to chop and cure. Glass jars etc. Keep closed but be sure to open and let plants breathe at least once a day and give em a little shake to make sure the moisture isnt trapped at the bottom. Id let them cure like this for at least 2 weeks, more is better.
Great job getting the purple, its beautiful. ✌️💜