Step 1 Using utility knife, cut paint where mouldings meet the wall and door jamb.
Step 2 To avoid damaging the wall, slip the wide scraper behind the chisel when you pry off old mouldings. Use pincers to remove any nails.
Step 3 Install architraves first. Use mitre box and handsaw to cut architrave to size. Run a bead of construction adhesive along back of architrave. Position architrave so mitred join is neat, then nail in place.
Step 4 For skirting, begin with external corners. Measure from corner to outside face of skirting on adjacent wall. Mitre cut at end of new skirting. Working from the cut, transfer measurement to new skirting and cut square. Run adhesive along back and nail in position, making sure external mitre is neat.
Step 5 At internal corner, use a scribed joint rather than a mitre in case corner isn’t exactly 90°. Cut a length of skirting at 45° as if for a mitre. The line where the angled cut meets the face reveals the moulding’s profile. Using coping saw, cut profile shape, undercutting slightly to ensure a tight fit against adjacent board.
Step 6 If skirting meets a doorway, measure from face of adjacent board to architrave. Transfer this measurement to skirting and cut square. If going to another internal corner, measure to corner and make this the square side of another scribed joint. Push scribed cut into profile of adjacent board then nail in position.
Step 7 Fill nail holes, let dry and sand smooth. Apply undercoat, then 2 coats of indoor enamel, letting dry between coats.