"It's all very well getting a job. Now you've got to do it," he said.
Ryan said his long-time coaching partner at the Crusaders, Scott Robertson, had been supportive when they met and talked about the offer from All Blacks coach Ian Foster.
Ryan said he was loyal. Robertson had done a lot for him in their time with the Crusaders.
"It's a chance to coach my country, and it's a dream to always be an All Blacks forwards coach. I can't wait to get into it," he said.
Since joining the side for their Wellington camp this week, Ryan said the job was everything he expected and more.
"The boys are really diligent. They care a lot. They know where they need to be, but we've got to go and prove it."
Ryan said the forward pack had been dented.
"We talked about in the forwards meeting [on Monday]. We didn't hide anything. We were really honest. And we have to be. We have to get on with it," he said.
He was confident they could quickly get better.
Mauling would be front and centre after the damage done to the side during the two losses to Ireland in that area.
"We've got to stop mauls, that's for sure," he said.
"There's a bit of work that needs to go into that and our contact area. We've stripped a little bit out and concentrated on a critical few things.
"Getting them to understand what they're trying to achieve, and believe in, has been the big one, and being a bit clearer on what we're trying to do, which will help our contact area," he said.
They would be working on developing what worked for them.
Compared to the success the Crusaders have enjoyed through building over a long period, the reality for the All Blacks was they faced a Test in South Africa in just over a week.
"We've got to get a few critical things in place really quick. I'm confident we've made some progress on that.
"There's no better country or team to test yourself as a forwards coach. It's about where this team, and the forward pack, is. We've got to be fast learners.
"We've got immense respect for them, so we're looking forward to getting over to South Africa. There's nowhere we'd rather be," he said.