API work - updating how forms are processed and redirected with data sent to Salesforce

We have some forms on BioSpine.com that feed data to Salesforce. Our current API developer is not available for changes. Currently if you look at the sidebar form at biospine.com - when that form gets filled out, the data is sent to Salesforce and then you are redirected to a second form with more information that also gets sent to the same record in Salesforce. We need to update this so that the secondary form is dependent on what they choose under the "Type of Request" dropdown. You will be working on a staging server to start and then will guide me to make the same changes on the live site.