You cannot delete something from a packet once it's created. However, you can create different versions of a packet.
For example: if you don't always need to include a Lead Based Paint Disclosure, you can create one packet called "Purchase Agreement & Lead Disclosure" that includes the Lead Based Paint Disclosure and another packet called "Purchase Agreement & Standard Disclosures" that does not include the Lead Based Paint Disclosure, but includes all the standard disclosures for every agreement.
Then, you can send whichever packet you need, depending on the deal.