@mirsy That's excellent news.

Everything I'd read beforehand said to use one hand to hold the 2 tubes at the top of the device (did he give you a model of the device, so you know what it's like? Here's mine) to steady the thing - it's pretty slippery in there - and the other hand to squeeze the pump.
I found pretty quickly that I could use one hand - 3 fingers to pull the device to the side & use the thumb & finger to squeeze the pump.
It's easy to push. Too easy, in my case. They say give it 2 or 3 squeezes, but mine often works with one. It's just a rubbery button.
The button on the right there is the activation button. That's rarely used.
The squeeze part is the flat bit on the left. Push it a couple of times until it leaves a small dent. It refills on it's own in about a minute.