How to issue a CPFP?
From the glossary:


  Selecting transactions for mining not just based on their fees but
  also based on the fees of their ancestors (parents) and descendants
  (children).


Thus, we understand that this is a policy that is implemented by a miner.
Now, the way we can ensure that our stuck transaction falls under this policy is by ensuring our stuck_tx has a child_tx with good fees.

For creating a child raw transaction, we just need the txid from the stuck transaction and new address to send it. Put the funds, the change, what's left is the fee. Sign it and broadcast it.

To determine the right fee and more details check this fee bumping page on bitcoin wiki.