How to add PayPal Pro as Gateway in Membership Plugin.

Only PayPal Express and Free Subscriptions are listed in the gateway. I noticed that in the membershipincludes/plugins folder there is a paypalpro.php. How do I activate that? I hope I'm not just being stupid, but I've read all the documentation throurougly and I don't find the information anywhere!

Also, I have spent an hour searching the forums and I didn't find it either. I love the plug-in by the way! It was my primary reason for spending $419.00... and so far I'm very glad I did!

Please advise quickly. I'm under a deadline and I'm hung-up on this paypal pro thing.