With the battery tray removed, you now have a good look at the Air Pump and the bracket that holds it to the car. The two bolts that hold the bracket to the car are 12mm, remove them.
With the 12mm bolts out you can maneuver the Air Pump and bracket to a position similar to the above picture so you can cut the clamps that hold the hoses to the pump. The large hose is the input and the smaller hose is the discharge. The Pump is more than likely filled with water, so it is a good idea to take the caps that are on the new pump and have them handy to put over the inlet and outlet when you remove the hoses.
Once the hoses are off the pump you can bring the pump up further so that you can begin to disconnect the wiring to the pump. There are two wire holders in place, you can release them from the frame by using a small set of needle nose to pinch the connection on the back and it will come unclipped from the frame. The wiring has a small black wire that is grounded to the car; undo the 10mm bolt that holds the blue battery ground and black Air Pump ground to the car. One the clips is not attached to the frame; you need to open the tie-wrap enough to slide the small black grounding wire out of both clips. The ground is going to come out with the Air Pump. Note that on the 1998 there is no black grounding wire to remove and no relay attached to the frame, just a connector for the pump.
Once the black ground wire has been removed from the wiring harness you can now un-plug the two left connectors in the picture that are plugged into the relay.
With the pump out of the car you will now have to remove the bracket and relay. Unplug the connector in the relay and then remove the three 10mm nuts that hold the bracket to the standoffs on the pump. Once the bracket is off, you need to remove the standoffs from the pump. The standoffs are 16mm, but with the rubber on them, a 17mm wrench works to break them loose to unscrew them.
With the bracket, standoffs, and relay removed, you are now ready to attach
the new pump to the bracket. Install the standoffs (17mm), and then the bracket
(10mm nuts), and the new relay. Assembly in reverse order applies. Before
securing the clamps on the hoses, make sure the hoses will not twist when
you slide the pump back into place, especially the discharge hose. Don't forget
to plug in the power to the cruise control pump and attach the vacuum line
to the pump as well. While the battery tray is out, it is a good time to inspect
the vacuum line to the cruise control pump, especially where it routes under
the battery; this is where they tend to crack and break.