I recommend pinning the parts together before sewing the animal together. This will give you an idea of where you'd like the parts to go before assembly.
Attach the ears between R11 and R15, one on each side of the head, at a slight diagonal.
Attach the horn in the middle of the eyes, between R13 and R18.
Attach the body to the head, between R14 and R18.
The front of the head will be slanted down a bit. Make sure to stuff the body really well, this will help with the stability of the head. You can also sew around the body twice for extra security.
Attach the front legs underneath the head, one on each side of the body.
Attach the back legs between R6 and 9 of the body, on each side of the body.
Weave in all the excess pieces of yarn into the body. Please be aware that amigurumi contains small pieces and can be dangerous to children. If you're selling this stuffed ami, please place a warning and also state that safety eyes are not recommended for anyone under the age of 3.