Welcome Moose. Depending upon whether you are installing stiff, or regular shafts the tip trimming for Recoil shafts can be found here.
https://www.golfworks.com/images/art/shaft_trim_inst.pdf
You will need to tip trim if necessary, then cut the butt end of the club for the desired length. Standard lengths for graphite and steel irons can be found here, along with other articles from the Maltby library.
https://www.golfworks.ca/clubmaking-help-info/a/1652/
If the clubs are for yourself and the shafts are still on you may want to measure each club for length.
I did not find the exact model of Recoil your installing. But someone will chime in on the Recoil 780 ES.
-Bill
Thanks a million. Wish me luck.