depends on how much gas you want to get squirted with... I'd relieve tank pressure but line/engine side pressure really only matters if you don't want to get soaked with gasoline
Oh yeah... you have the old style tank so what I'm about to suggest is easy - replace the rubber line between the fuel pump and the fuel filter while you're under there, it's probably all crunchy and dried out and about to pop on you.
I usually just use a vice grip on the rubber lines to pinch off and pull the filter then cover the filter ends with my fingers until i get it to a bucket, you would be surprised how much fuel is in that lil sucker.