FPR install tips

Can anyone answer a question for me?
Is it necessary, or just easier, to remove the fuel rail to properly install a fuel pressure regulator on a 2.4 4 banger of '99 vintage?
I'm having a hard time getting the seal at the bottom lined up and sealing.
I'm relatively certain that I'm not an idiot with tools, as I work on semi's for a living.
What am I doing wrong?

Never had to remove the fuel rail....it is a tight fit...make sure you lube the o-ring....might try just loosening the two bolts that hold the rail in place, to give a little wiggle room....