The right tool makes all the difference. Allen head sockets and an extension and you'll go right in. Also its called an "Adjustable Fuel Pressure Regulator" or "AFPR". Kirban has been the best one I've used. Hopefully you do not have a BBK or a generic one...
2000 Mustang GT Steeda #0048
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.