Buy a ratcheting plastic pipe cutter. You can get them for $8-$100. Mine cost $8. If you need the cutters you'll also need PVC glue and some pipe cleaner fluid. It is often dark purple in color. The cleaner removes the outer surface of the pipe so the glue will melt deeper into the pipe forming a solid piece after it dries. The rest of this I'm doing in steps to make it easier to sort out. I'm not trying to be pedantic. Find a riser you want to adjust the height on. Dig around that riser until you get to the cross connecting pipe underground. It will be 6-12 inches deep. Put all the soil onto a tarp or something that you can temporarily pull away. Measure the pipe diameter so you can speak intelligently with the people at the hardware store. Risers are usually 1/2-inch but rarely a 3/4 pipe is used. Measure the height of the riser from the TOP of the lower fitting to the TOP of the spray nozzle. Lay a piece of wood across the hole and measure from the top of the bottom fitting to the bottom of the wood across the hole. The bottom of the wood is the very top surface of the planet at the location of that hole. You want the TOP of the sprayer to be at that height. At this point all I can say is you are going to get some experience. Adjusting the height of the riser might be as easy as adding a threaded "nipple" to the top of the riser or you might have to do some surgery with your pipe cutting tool. If you have to shorten the riser, you will need to cut it twice and remove a piece in the middle. Then you can rejoin the two pieces with an unthreaded nipple (need the glue and cleaner). Or you can cut off the top fitting and glue a new one on at a lower height. Use the measurements you made to determine the final length of the riser when you are finished. Make all your cuts leaving the riser as long as possible. It's much easier to work at the top of a hole than at the bottom. There are many ways to approach a fix. Go to the hardware store and start memorizing the types of fittings you have available. There aren't that many but the combinations of threaded and unthreaded are important. When you are finished you will have dirt left over that will not fit into the hole. This next part is very important. ALL THE DIRT GOES BACK INTO THE HOLE. That is why the tarp was important so you don't lose any of that dirt. If you do not put all the dirt back into the hole, you will soon enough have a depression around that riser. Even though you have a mound around the riser and the spray nozzle is below grade, all that dirt will eventually settle back to where the edge of the planet was when you started. You will pay for the cutting tool the very first time you use it. The alternative is a hacksaw that usually ends up breaking pipe and fittings as well as delivering bloody hands. The cutter goes through pipe like a hot knife through butter. When I was doing this in the '60s all the pipe was galvanized steel. Hacksaws were required so the hole had to be big enough and deep enough to get a hacksaw in there. If the pipe was old enough you usually ended up replacing the horizontal pipe, too. What a MESS! Life is better with plastic!

Ok - there is a trick to this, but it is a pretty stupid trick. Basically, you put out some cheap seed (like K31) and hope for the best. When that doesn't work, repeat. (See, I told you it was stupid!) Eventually you get lucky and mother nature cooperates enough to get some decent grass growing. What usually happens is that you get some sparce grass now and it starts to come in better through oct and nov. Between washout thunderstorms and long dry periods, you'll probably have to do it a few times before you luck out, but you never know. Of course, the drought could continue through the end of the year an mother nature never cooperates with a few rainy days in a row, but that is the risk you take if you can't/won't water. Another method is "dormant seeding." Basically, wait until late fall and put out a bunch of seed. Wait for spring and wet weather. That tends to work better in northern climates where snow protects the seeds over winter.

I'm not sure what forum would be the best to get an answer for that. Did you have a question about how to make your lawn better?

We do it in late February / early March for St Augustine sod. Not sure of benefit of summer aeration, may promote root dryness, which not good. You have provided good caution about doing this when soil too dry, esp. If clay soil, but also unwise when soil too soft. We've done it in such conditions and the plugs stick to your shoes and make a holy mess!