Here's your access to the best real estate exchange and reverse exchange companies serving Contra Costa County including 94565, 94509, 94806, 94513 and 94553. Official Forms for Viewing and Downloading.Sellers who need help in completing their disclosure obligations should consult with their own qualified,. To download this guide as a PDF, fill out the form below. The primary objective of this exchange is to postpone the capital gains tax on the sale of the relinquished property.