You must test the water the same as what you test a baby bottle, use the bottom of your wrist to test it. You must remember that they are cold blooded, if the water is too hot or too cold it will damage them, I dont want to go into that detail now.
It must be warm enough so you can stick your face in without burning.
He will hate it, he will want to run, he will wiggle, you must just stay calm. Lower him into the bath very-very slowly and scoop a little bit of water over him so that he can see it is actually nice. My ig still hates bathing, he only showers. Keep your hand and arm facing towards you and let Diesel rest on it, it will give him security in the water. If he tries to get out, then you must put him back, unfortunately.
Some igs love bathing, hopefully Diesel will be one of them.
I am too emotional about animals. Please forgive me for thinking with my heart.
Linky