To do the recast & commentary successfully, you need to:

• Select your information from the text(s) well
• Decide on a few linguistic tricks for your audience
• Make sure all relevant frameworks are covered in the commentary (which will include some grammar - integrate it with other frameworks if at all possible)

The key things about the actual writing are that you must:

• Use information from the text(s)
• Adapt the language of the text(s) to suit your audience, purpose and genre
• Not add in facts/information of your own