Set a 1-by-4 board along the bottom edge of the wall to give you the required 3/4-inch space from the floor to the bottom of the drywall.
Stand the first sheet in place at one end of the wall and check to see that the far end stops in the center of a stud. If it does not, measure back to the center of the next stud, and mark the sheet that far in from the first edge. Always put cut edges at a corner.
Use a drywall square to mark from top to bottom at the marked distance from the edge. Drag the point of the utility knife along the line, scoring through the paper. Repeat this until you cut about a fourth of the way through the sheet.
Press back sharply along the edge of the sheet to break the drywall along the scored line. Run the knife along the back to cut the paper.
Reset the sheet, if it was cut, and drive 1 5/8-inch drywall screws through it into each stud behind, every 10 inches of height, using a cordless drill. Drive the screws in until the heads are just flush with the surface.
Remove the 1-by-4 and slide it over to brace up the next sheet. Set the next sheet in place and repeat the process, screwing it in place in the same way. Add full sheets as far as you can. Measure and cut the last sheet to fit, as outlined in Step 2, and screw it in place.
Scoop premixed drywall compound into a drywall knife trough. Use an 8-inch-wide knife to spread drywall into the first seam between sheets, filling the tapered area along the edge of each sheet.
Cut a piece of paper joint tape to fit from floor to ceiling, using the utility knife. Paste the tape into the compound, dragging the knife along it, to press it into place.
Add a thin layer of compound over the tape and drag the knife down to level it off, even with the faces of the two sheets on either side. Fill the remaining joints in your wall in the same way. Allow the compound to dry thoroughly and sand it smooth with a random orbit sander and 150-grit sandpaper.
Spread a third, thin coat of compound over the sanded joints to fill any unevenness in the surface. Allow it to dry. Then sand again.