How to fit skirting boards
The renewal of skirtings is a fairly straighforward job but please take your time so that you don't damage the existing wall when removing the old existing skirtings.
1. Cover all your work area with dust sheets, protection is better than cure.
2. Using a sharp putty knife (or a craft type knife similar to a stanley knife) place it between the edge of the skirting and the wall to cut through the paint or wallpaper.
Follow the same procedure for all of the edges to each length of skirting.
3. Use a crowbar to lever the existing skirting board away from the wall, a broad chisel or bolster can also be used to then allow you to insert blocks of wood to create a gap between the boards and the wall so you can cut the skirting board as required.
Skirting boards butted against the door architrave are easier to lever off. Longer skirting boards, with ends joined in internal corners of walls, will need to be sawn or chiselled off and removed.
4. Cut off the skirting board at a 45 degree angle across the thickness of the board and completely vertical if you intend to renew only a part of the length.
5. If you plan to lever the top edge of the skirting board, carefully tap between the skirting board and the wall with a chisel and hammer.
6. To protect the wall from dents while you remove the skirting board with the chisel, slide a piece of thin wood between the blade of the chisel and the wall
7. Gently tap the side of the skirting board to loosen the nails that are securing the board to the wall.
8. Remove the nails with pliers, depending on the nail type it may be better to us a hammer claw.
9. Measure the length of the wall where you plan to fit the new skirting boards.
10. For scribed, butt-jointed and moulded skirting boards at internal corners, you'll need to cut the end at 45 degrees, and cut along the contour line on the moulded face with a saw. You can use a mitre box to achieve an exact 45 degree angle cut, or you can fit one length of skirting and simply flase mitre the very top of the skirting in readiness for the 2nd walls skirting to be butted up with a matching false mitre.
11. Skew or cheek nail the skirting board on the wall.
12. Apply a thin coat of primer (if painting) before you decorate your new skirting boards.Lots more diy info here and advice on fitting matching architraves is located here.