On your 1998 5.2L engine there is a heater hose that comes off the water pump on the drivers side. There is a single bolt that holds the small metal tube onto the block where the hose fits onto the pump, put if you remove that single bolt that tube will just pull straight out and there is an O-ring on it. Replace the O-ring with a new one. You can go to a auto parts store and have them pull a new pump and open the box. From there you can see what size O-ring you need and just purchase that O-ring and have them put the box back on the shelf.

Now when you pull it there will be a bunch of coolant come out on both sides but the hose won't be too bad, however the pump side will pour. Just hold it with your finger and have someone remove the old O-ring and place the new one on, lube it lightly with a little grease and stick it back into the hole and bolt it back down. Should take you 5 minutes to actually fix it.