Translation of rocín

Let me know, once you want to proceed. Probably I did not explain myself well enough in the mentioned issue. Lili, can you please print the attachment and go over all the wrong expressions and words?
The climb was much exhausting than I had presumed. I had forgotten that we were at high altitude where there is less oxygen and that every step required double effort. It was a great exercise.
We managed to get a few hours of bad sleep and arrived at the destination called Lao Cai, the capital of the province with the same name. It was only 370km from Hanoi, but the ride lasted nine hours.