If an agency makes a change to a solicitation once it has been created, they must issue an addendum for the solicitation changes. If you have submitted a bid, you will be notified via e-mail of the addendum, and you should then go to the website and review the addendum.
To do this, log into the website, then find the solicitation in the My Current Bids list. Click on the title of the bid for the solicitation summary page.
Then, click on the Addenda link along the top. There, you will see a list of any addendum documents that have been uploaded to the site. Click those links to view the documents.
After reading the documents, you might want to edit your bid. See the previous page on Editing an Online Bid for instructions on this.