Step 1: Click on the Presented Proposal then click the Edit button:
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Step 2: You will receive a warning which indicates that if you continue to edit the proposal you will remove price adjustments, the proposal will re-calculate the price based on newest costs/margins, the products availability will update. To proceed click continue:
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Step 3: Here the proposal will be in draft status which will allow you to make the necessary changes:
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Feel free to reach out to the Customer Success Team for any questions.