# They brought the colt to Jesus
The word "They" refers to the two disciples.
# threw their cloaks on it, and he sat on it
"laid their cloaks on its back and Jesus sat on it." It is easier to ride a colt or a horse when there is a blanket or something similar on its back. In this case, the disciples put their cloaks on it.
# cloaks
"coats" or "robes"