If you see PayPal in the item listing under payments, you should be able to use PayPal to pay at checkout.
There is no need to do anything to your account settings; simple choose PayPal at checkout.
From time to time a problem with a particular payment method can prevent eBay from connecting to that service for a brief period -- in that case, the logo may be removed from the listing, and that payment method may not be available in checkout until service is restored.
If you do not see the PayPal logo in a listing, wait a bit and try again. If you do not see PayPal back within 24 hours, you may have to try a different payment method.
