Can somone give a simple step by step method for combining and detaching then recombining task groups.
Unlikely, as unless you have just the right fleet set-up there aren't enough default & conditional orders to handle it, and repeat/cycle orders can't be modified to send you through the correct jump points. Which means that the problems you're having are at least partially based on your fleet composition, without which we can't really help you. What I mean is, I'll say "Do this, this, and this," and you'll come back and say "That didn't work."
Anyway, I assume you've tried:
Move to Jump Point X
Transit Jump Point X
Separate into single ships
Default order 1: Survey nearest/next 1/3/5 whatevers
Default order 2: Combine with parent fleet
Conditional 1: refuel at nearest tanker