Osaka Castle access for seniors

We are in our 70s and would like to visit Osaka Castle utilising public transport from the cruise ship terminal. I understand there are a lot of stairs to negotiate but that there is also a lift for access.
Could you please advise me of how difficult the walk would be. We are able bodied but would require rest stops if there were a lot of stairs or long distance involved. Do you think it is suitable for us? The castle and its grounds look amazing and we would love to go there.

From the cruise ship terminal, take Osaka metro Chuo line from Osaka-ko to Tanimachi-yonchome. No transfer needed. I believe there are lifts in both stations. From Tanimachi-yonchome you will walk 1.2 km to the castle.

I guess you are asking about stairs INSIDE the castle. Well I remember (and deeply dislike Osaka castle for this reason) , that there is a loft inside. Reason; this �gcastle�h was built in concrete and is really only nice to look at from outside.

https://www.japan-guide.com/e/e4000.html

Thank you for your responses. I understand there is a lift inside but when walking to the castle are there many stairs?
From the second answer are we better to just view the castle from the outside?

The park is relatively big but generally flat. There might be a few steps here or there but nothing massive.

The castle and park are slightly uphill, but they are accessible/barrier free.

West entry of the park:
https://www.google.com/maps/@34.685037,135.5220973,2a,75y,79.39h,86.49...

Gate leading to the castle:
https://www.google.com/maps/@34.6848624,135.5257141,2a,75y,356.12h,94....

Stairs to the castle (there's an elevator on the left):
https://www.google.com/maps/@34.6868928,135.5259637,2a,75y,346.92h,103...