On this occasion I had to take him out of the cage while I did it. He doesn't like seeing things being done inside his house. I put him in his playpen with some toys in the other room. Stepson was in there to keep an eye on him.
If it's something more major like a substrate change or a new set up that will take a while I put him in a spare smaller cage with substrate and some food and water and a wheel. He tends to make a temporary nest in there.
With our last Syrian I used to put him in his pet carrier in another room with a blanket over it and he'd just go to sleep. Newt doesn't like that and doesn't go to sleep so he gets the spare smaller cage for a few hours
