You can delete your payment form by clicking the EDIT option available in the Update Auto Renewal Payment Method section of your Account Home page of members.iracing.com.
Click EDIT and you can then choose the red X to remove your payment form.
Confirm deletion and it should then be removed.
If you purchased with Venmo, please go to 'Settings' in the Venmo app and tap on 'Connected Merchants'. Select the merchant you want to stop making purchases with, and tap 'Disconnect' at the bottom of the screen. Even if you disconnect your Venmo account from iRacing, it may still appear as a payment option. However, iRacing won't be able to charge your account if you've disconnected it through the Venmo app.
Please know that if you have auto renewal activated and you remove your renewal payment method from your account, the auto-renewal will fail and you will need to renew manually.
If you have any further questions, please reach out to firstname.lastname@example.org