make sure you have a hitch up high he can grab onto.
Google Pouch evac. I have done it, its not hard, just a little scary since you dont want to hurt him. what I did was gentle grab him under water and used a bobby pin to gently open hi pouch a little and squeeze the air out.'
Watch him though, you may need to do a diomox treatment on him. I may have a couple if you need them, I will have to look.
T