Clean the unfinished attic out, leaving only a blank space. Sweep the floor if it is already installed.
Attach plywood to the roof trusses, the walls and then the floor using a nail gun with stainless steel nails.
Hang drywall against the plywood on the ceiling and walls using drywall screws and a screw gun.
Tape the joints between drywall sheets with drywall tape, then cover the tape with joint compound using a putty knife. Sand the compound with medium-grit sandpaper once dry.
Line the edges of the plywood floor with carpet tacking, then install carpet padding inside but not over the tack strips.
Roll out and stretch carpet over the tack strips. Tuck in the edges of the carpet between walls and the tacking, then cut off any excess with a utility knife.
Spread drop cloths over the attic floor and pour paint into a paint tray, then paint the ceiling and walls using a roller to finish the attic remodel.