drop the tank and take the old pump out then put the new one in
A mechanic, that's who.
To replace the fuel pressure regulator on a 1999 Pontiac Firebird, first, relieve the fuel system pressure by removing the fuel pump fuse and starting the engine until it stalls. Disconnect the battery, then remove the intake manifold or the necessary components to access the regulator. Unplug the electrical connector and fuel lines from the regulator, then remove it from the fuel rail. Install the new regulator, reconnect the fuel lines and electrical connector, and reassemble any components you removed before reattaching the battery and testing the system for leaks.
what year?
yes it is fuel injected.
There is no fuel pump shut off switch on a Pontiac Firebird. Instead, it has a fuel pump relay under the hood in the power distribution box.
15.5 gallons
Yes
The fuel pump in any car is tricky, using its diagram can make the repairs easier. The diagram for a 1995 Pontiac Firebird fuel pump can be found in its maintenance manual.
In the fuel tank
In the fuel tank, integral to fuel pump.
15.5 Gallons
Does it crank? do you have spark? fuel?