Shut off the water supply to the tub prior to doing anything. Then remove the panel or surround encasing the tub and the faucet spout and handles. Use a wrench if these items are difficult to remove. Use a pry bar to separate the tub from the floor, and remove the tub from the bathroom.
Design the shower using software as a guide. Smart Shower is an example of a shower design software that helps you create the best design to replace your existing garden tub. Using this software, you enter your measurements and it creates installation instructions.
Create the layout for the shower using masking tape. Include the angles and connecting sides from your plans or design. Mark angles and other parts of the layout on the masking tape; you will remove the masking tape later.
Use 3/8 inch to 1/2 inch thick tempered glass as the walls of the new shower. Using the weight and size of each glass shower wall or door, determine how many hinges you need. Geneva hinges support 80 pounds. When there is not a header or wall mount, use top and/or bottom pivot hinges.
Install a drain, shower faucet and head, and shower pan liner to convert the tub area to a shower. Build a shower seat bench in the shower pan using mortar, concrete blocks or bricks and tile. Tile the rest of the shower up to the ceiling.