Just cut up the pattern and sew according to the pattern. It’s very easy.
To make more of a caplet like I made just add one button and buttonhole at the top corners instead of the two down the front that is shown in the pattern directions.
For the bunny tail I made a little circle pattern by tracing a circle from a glass (you could totally free hand it).
Then I cut a circle of fleece and safety pinned them onto Teddy’s pants.
If you want more of a poof style you could make a large pom pom out of matching yard.