What of the below procedures takes 20 min? or which one should I apply to check or replace the front drive shaft with a repaired one?

1. pulling the exhaust
2. pulling a couple of large heat shields
3. pulling the rear drive shaft
4. remove the transfer case crossmember
5. split the trans and case to get a front drive shaft out

or this one:
1. remove the front stiffener plate
2. undo the bolts at the front driveshaft flexdisk
3. slide the shaft backwards until the flexdisc can slide out (it has a centering device that sticks into the flange on the front differential preventing it from just dropping out).