Having a shower stall and a separate bathtub is convenient, but many homes and apartments do not have space for both. The solution is to have the shower fitted over the bath. You will then need to erect a shower screen over the edge of the bathtub. There are two types of shower screens, fixed and flexible. The fixed variety is attached along the edge of the bath and cannot be moved. This is a good way of preventing water from escaping, but can make cleaning the bath a bit of a chore. A flexible shower screen can be moved inward or outwards to allow room for cleaning.
For flexible seals, place them in a tub of hot bath water until supple. Take the seal and coax gently onto the top and bottom of the shower screen. For rigid seals, slide the plastic seal along the upper and lower edge of the screen and trim to fit using a hacksaw.
If there are no hinges fitted to the screen then clip the seals into a place a couple of inches from either edge of the screen. Clip them in top to bottom.
To mark the position of the wall fixings hold the screen above the side of the bath in position. Mark clearly on the wall where the hinges sit against the wall.
Drill holes into the wall or tile and insert wall plugs.
Holding the screen in place, insert the screws and tighten. Attach top screws first so that the screen will hang.
Remember that hinges will only swing one way, so double check that the screen is installed the correct way up and that it can be swing away from the bath for cleaning purposes before fixing to the wall.
For rigid seals, use a small amount of sealant to prevent water from gathering into the foot of the seal.