After the trust has been created in Step 1 with a single Beneficiary which is the Seller we move to Step 2 where will add an additional Beneficiary.
The Buyer in the transaction becomes Beneficiary 2. For consideration ( their down payment) they become Beneficiary 2.
Now that the trust has 2 beneficiaries the decision making process is divided between both Beneficiaries. Each Beneficiary has an equal say in how the trust operates.
The Beneficiaries can change any part of the Trust and/or Beneficiary Agreement as long as they both agree. Neither Beneficiary has more control over the trust than the other.
No changes to the trust documents can be made unless there is complete agreement between the Beneficiaries.
Most trusts never need to be altered in any way. Normally, all of the terms and conditions of the trust have been worked out prior to the formation of the trust.
Most of the changes made in the trusts are minor in nature. An example would be a name change if one of the Beneficiaries gets married or divorced. In those instances the Beneficiaries would simple put in writing what needs to be changed, sign it and send it to the Trustee. The Trustee would then modify the documents accordingly.