I'm no expert, but you should be able to do this fairly easily. Assuming you just need a new head. I would start by watching some videos on Home Depot, or Lowes, or other trusted site. They make it easy, give good overviews, and only take a few minutes. If you don't understand something, google it and link to a plumbing site. Pick out your new head and read the instructions. You might need some special tape, but it's very inexpensive.

It's been a long time since I did this, but I don't recall needing much, maybe just a wrench?

If you need to also change out the shower arm, that's a little more complicated. I haven't done that, but I would guess it requires making sure it is drained first. Probably not hard at all, but a little more involved.

jardinista: "The shower was installed about 7 years ago and about a week ago,water pressure decreased dramatically!,only in the shower."

The problem could be in the shower head. As, or perhaps more, likely, it is in a filter/trap right before the mixer. Some scale broke loose from the upstream pipes and clogged that filter. Most modern shower components put a filter there, actually two filters: one each for hot and cold incoming lines.

Those filters are not difficult to clean, and only a little more difficult to locate to determine if they need cleaning. But, because they precede the on/off valve of the fixture, you will need to turn off the water supply before you remove the filters for cleaning, unless you want a lot of water on the floor and perhaps inside the walls. If you remove the decorative covers around the mixer, you should find the filters quite easily.

If the clogging debris has got as far as the shower head, most shower heads are simple twist off, twist on replacements, just one step more complicated than changing a light bulb. You will need a length of teflon tape (available at any hardware store) to wrap around the threads of the pipe that comes out from the wall before you twist the new shower head on.

My (personal) recommendation for a replacement shower head -- IF you need one: the Moen Velocity 6320.

This post was edited by herring_maven on Wed, Dec 26, 12 at 23:14

OK Herring Maven--town water rep. came out yesterday. I was not home,husband was. So,It's not the shower head,husband claims they took it off and it's fine. Problem is lower,a clog. So you may be right on about being a filter. You give a good idea of what's involved,but isn't all that behind the tiled wall?? How is that a DIY thing?? Thanks for info. Jardinista

jardinista: "You give a good idea of what's involved,but isn't all that behind the tiled wall?? How is that a DIY thing??"

My impression is that it is mainly a function of the age of the fixture. The situation is like the prevalence of electric motors for car windows, which used to be a luxury accessory and relatively rare, but when was the last time you saw a new car with window cranks? Our old shower had everything behind the tiled wall, but we remodeled the shower in 2002, and the new fixture that we put in, a Hansgrohe: (1) had line filters -- the old fixture had had no filters before the showerhead itself -- and (2) because it had filters (which need to be cleaned periodically), the filters were made accessible behind the decorative plate around the mixer handle. My assumption was that your seven-year-old shower fixture would have conformed to the modern practice.

If you look at the link below, that oval plate comes off by unscrewing a single screw, and behind it is the guts of the mixer within a cavity. Within the cavity, the cold water line is connected on one side and the hot water line is connected on the other side. Where the lines connect to the mixer, there are snap-in filters (they have rubber gaskets); be sure the water is shut off to the line, and simply snap the filter out of its seat, rinse it off, and snap it back in. Turn the water supply back on, replace the decorative trim, and you are back in business.

Here is a link that might be useful: A Hansgrohe brand shower mixer.