Setting up Stripe is a pretty easy process.
Login to SiteWrench and go to: Settings > Tools > Payment Gateways.
Choose Add a Payment Gateway.
Give it a Name
Choose Stripe as the Gateway Type
Next, select the "Connect with Stripe" button and follow the step-by-step process.
If you have a Stripe Account you can login. If you don't, you can complete the account creation process while connecting Stripe to SiteWrench.
When you're done, you can use this merchant account to accept payments with the Forms page part.