Ok I suspect this is a really stupid question, to which is either
A) muscle memory and the practice or
B) get a friend to help you
But … once you’ve drawn your thrown off the pack, done what needs to be done … is there an easy way to get it back on the v-hook?!
Cheers!
It is best to have a friend re-holster it for you.
That being said, if you really need to do it solo, reflections are your friend. If you can’t get to a mirror to look at what you’re doing, a car window can sometimes work in a pinch.
Be prepared, though, for the inevitable ‘half-holstered’ which you THINK is in there good, and a few minutes later it hits the floor.
Alex
I have never been able to do it and need a friend to put it back on. Either that or walk around holding the thrower 
Last Halloween I found myself slipping the left shoulder strap off just to make sure the v hook on the wand was set in place to holster it!
The key fob is great if you’re tired of holding it but with the weight of the gun it was pointless to try to walk.
I would just slip one strap off like I am taking the pack off and holster it
Funny you brought that up Alex. I thought my wand was secured on the pack and even ask my friend if it was on to which he said “Yeah it’s on” only to slip off the left strap and see it was half-holstered!
Only one of my guys can do it and even then hes only been able to do it once. Like Alex said, have a fellow buster holster it for you.
Usually I ask my wife or whoever I’ll with to put it on. But I remembered not long ago that as a kid I had to take my arm out of the left strap to get a look at the hook and put the thrower on. To my surprise this worked extremely well as an adult, too.
I added a strong magnet inside the v-hook on the pack which helps guide the track by locking onto the screw. it helps when doing by myself but still not worry free. Maybe Ill find a way to make it better.
my go to method, like glenn mentioned, is to slip off the shoulder strap so I can see it go in correctly.
The best method of hanging the thrower from the belt is to utilize one of the GB2 v-ring fobs on your right hip; this will angle the thrower out of the way and keep it from bouncing on your leg when you walk.
I managed to hook the gun onto the Pack once, although this was the Spirit Pack. 
I talked about this thread/topic in the latest installment of My Ghostbusters Pet Peeves…
https://www.youtube.com/watch?v=hif5zc2Ts-Y
Enjoy!
Alex
Cheers Alex! Feel a bit honoured to have one my Q’s answered by one of the big names of the GB world
Seems like team work is the key to this!
Cheers