Have you got the sleeves made and attached? Bottom-up raglans have you knit the sleeves up to the armhole, then attached them and knit from there up in the round as well. Here
is an example of how that is done. If you do have it done that way, you can use the decreases that are in this pattern for yours.
Another option is to stop knitting in the round and knit the front and back separately, back and forth as you would if you were knitting flat.