Sometimes, after the original offer is made and accepted, a re-negotiation takes place and a new offer is made. In order to do this within Lifesycle, start by going to the Sales Progression.
Click on Operations on the left side
Then choose Sales Progression
Search and click on the three dots to the right of the property, choose detail and scroll to the bottom to see Re Neg.
In the pop up, put in the new offer information and click save. This will update the price. You can send out the memo of sale with the updated price now.