This is a pretty easy job really. Ours was only complicated by some difficulty in getting the right size door and the fact that we would have to drill through the bathroom tiles to fix it.
Go to the shops with the required width of the door (wall to wall distance) in metric and imperial units, millimetres seem to be the most popular. All the doors are adjustable to some extent. This is normally done by getting a certain size door and varying the size of the frame that attaches to the wall and the door sits into. In our case, we got a 750mm door (that's its actual width) in a frame that could fix the total width anywhere between 755mm and 800mm. We had a 780mm gap. The doors are normally advertised as being a "750" or "800" doors but they all cover ranges of say 760mm to 800mm etc.
The only preparations are the precautions you should take before drilling into the tiles. We received strict instructions to scratch the surface of the tiles where they would be drilled through. The idea is to break the glaze and prevent the tile from shattering. You then cover the point of drilling with masking tape.
Makes perfect sense except that it proved to be impossible. We tried drill bits, stanley knives and nails but could not even mark the tiles. Masking tape was the only protection the tiles got.
The shower frame came with a supply of screws and the frame was predrilled. We simply put the frame in place,marked the masking tape through the holes and drilled SLOWLY with a hammer action drill. We put rawlplugs in the holes and screwed the frame in place. Simple really.
Mine is not plumb, use a spirit level or plumb bob.
For the sealing job, I got a hand operated "gun" and container of silicone sealant for about 7 quid. Don't forget to get the screw on nozzle for the silicone container. Make a small hole in the nozzle by slicing off the tip at about a 30 degree angle.
You now just squeeze silicone all around the door frame where it meets the shower stall walls and the shower tray. Inside of course, I also did the outside because I liked the smooth finish and applied small amount to the screw holes.
try and make a nice neat even bead all the way around. You probably won't make a perfect bead so smooth it off by running your finger along it leaving a concave smooth finish. Wipe off excess with a damp cloth. I recommend keeping a separate slightly damp cloth exclusively for cleaning your fingers. After about 10 minutes the silicone will start to "skin" over and you can't work with it anymore.
The key tip that most people now know is that you should stand in the shower while doing this. If you apply it with no weight in the shower tray, the silicone will be stretched and under tension when you do stand in the shower. The same applies to baths, you're supposed to fill them with water before sealing.
I had to go back and touch up corners and go along the bottom of the frame a couple of times before I plugged all ways for the water to escape.
Well that's it. Hope our experiences were some help. Add an entry to the guestbook if you have any comments.