1. Remove the sprinkler cover and put the new nozzle on top.
2. Place the filter on there to keep debris from flushing back up into the nozzle.
3. Replace the nozzle.
How to replace a sprinkler valve:
1. You can use a valve locator (similar to a metal detector) to find the valve.
2. Then you can dig up the valve.
3. Put a 6" turf box back on top of that valve.