Replacing the legs to your IKEA Karlstad sofa allows you alter the height and type of the unit. The legs on Karlstad sofas may be unbolted in the framework and replaced using different IKEA legs designed particularly for the Karlstad couch or using legs in a third-party manufacturer. The couch is hefty, so ask a friend that will help you move it about.
Lift the couch and lay it flat on its back so the legs stretch out horizontally. Lift it cleanly off of the ground before putting it down. Do not tilt the couch backward using the legs still on the bottom, since this can damage the bearings and leg-mounting bracket.
Insert the Allen wrench that came with the couch into the hole on the bottom of the initial leg that you want to remove. All the legs which came with the Karlstad sofa have holes on the bottom designed to ease their removal.
Rotate the Allen wrench counterclockwise to remove the bolt that runs through the center of this leg.
Pull the leg off of the framework. Repeat steps 2, 3 and 4 for every leg that you want to replace.
Line up the newest leg together with the holes on the bottom of the sofa framework. There are two holes at every leg-mounting location. The exterior hole is the main hole, and the interior hole is for extra support. Check the documentation that came with your replacement legs to determine which holes you need to use. If your leg only came with a single bolt, then line it up with the exterior hole.
Screw the bolt into the frame using an Allen wrench or, even if your bolt and elbow are just one unit, twist the leg itself until the top of the leg is flush with the frame. Repeat steps 5 and 6 for every replacement leg.