Skip the YT videos, and the 'template' stuff.
Just buy this, and knock it out.
https://www.ironrockoffroad.com/product/transfer-case-clocking-drill-jig.html
Took me all of 5 minutes to mount it up, and drill it out, and I did it IN the Jeep.
Buy 2 bolts & nuts from the hardware store, throw the jig on the back of the housing and use the two bolts in the existing holes to hold it up.
Then just take your drill and pop the new holes.
You can make your own template, but is this REALLY a job you want to accidentally botch?
The jig is well worth the $60 for the peace of mind that it's done correctly the first time.
View attachment 496983
View attachment 496984