How to expose only specific fields from a SFDC Object into Marketo?

Hi All,

I am trying to figure out how to only expose a specific set of fields from an object that can map to Marketo, but one that isn't a primary entity of our business. Essentially, I just want to be able to expose 8 of the fields from this object rather than all 200+ available.

Anyone know how to do this? I believe I need to go into SFDC > Manage Users > Profiles > (Our Marketo Integration profile), then I do not know exactly how to complete this.

Any help would be great!

Thanks!